function GoBack() 
{
        history.back()          
}               

function IsValidChars(str)
{
        if (((str == null) || (str == "") || IsBlank(str)))    //empty and required
                return false 
                
            return true
}

function IsBlank(str)
{
    for(var i = 0; i < str.length; i++)
    {
        var c = str.charAt(i)
        if ((c != ' ') && (c != '\n') && (c != '\t')) return false
    }
    return true
}

function IsMandatoryOption(optSource)
{
//This function returns false if none of the OPTION 
//is selected otherwise true
        var i=0
        for (i=0;i<optSource.length;i++)
        {
                if (optSource[i].checked)
                        return (true)
        }
        
        return (false)
}

function ValidateLength(str, blnMandatory, strMsg, intLength)
{
        var ret = ""
        if (blnMandatory == true)
        {
                ret=IsValidNumericValue(str,blnMandatory,strMsg)
                        if (ret == "")
                        {
                                if (str.length == intLength)
                                        return ("")
                                else
                                        return ("\n          " + strMsg)
                        }
                        else
                        {
                                return ("\n          " + strMsg)
                        }
        }               
        else
        {
                if (str.length == 0)    
                {
                        return ("")
                }
                else
                {
                        ret=IsValidNumericValue(str, false, strMsg)
                        if (ret == "")
                        {
                                if (str.length == intLength)    
                                        return ("")
                                else
                                        return ("\n          " + strMsg)
                        }
                        else
                        {
                                return ("\n          " + strMsg)
                        }
                }       
        }
        return ("")
}               

function CheckTextAreaLength(strTextArea, intLength, strMsg)
{
        if (strTextArea.length > intLength)     
                return ("\n          " + "You cannot enter more than " + intLength + " Characters for " + strMsg)
        else
                return ("")
                
        return ("")
}

function IsValidNumericValue(str, blnMandatory, strMsg)
{
        
        if (blnMandatory == true)
        {
                if (isNaN(str) == true)
                        return ("\n          " + "Numeric values for " + strMsg)                
        }
        else    
        {
                if (str == "")
                {
                        return("")
                }       
                else
                {
                        if (isNaN(str) == true)
                                return ("\n          " + "Numeric values for " + strMsg)                
                }
        }
    return ("")
}

function IsValidRange(str, blnMandatory, RangeMin, RangeMax, strMsg)
{
        if (blnMandatory == true)
        {
                if ((str >= RangeMin && str <= RangeMax)==false)
                {
                        return ("\n          " + "enter a value between "  + RangeMin + " and " + RangeMax + " for " + strMsg)                          
                }

        }
        else
        {
                if ( (str != "") && (str >= RangeMin && str <= RangeMax)==false)
                {
                        return ("\n          " + "enter a value between "  + RangeMin + " and " + RangeMax + " for " + strMsg)
                }
        }       
        return ("")
}

function IsCharExists(str, strChar)
{
        var i = 0
        temp=str
        j=temp.length
        for(i=0;i<=j-1;i++)
        {
                if (temp.slice(i,i+1) == strChar)
                {
                        return(true)
                        break
                }
                        
        }
        return (false)
}

function StatusMsg(str)
{
        window.status=str;
        return true;
}

function CheckBrowerType()
{
    // convert all characters to lowercase to simplify testing
    var agt=navigator.userAgent.toLowerCase();

    // *** BROWSER VERSION ***
    // Note: On IE5, these return 4, so use is.ie5up to detect IE5.
    var is_major = parseInt(navigator.appVersion);
    var is_minor = parseFloat(navigator.appVersion);

    if (is_major < 6)
                window.location.href = "http://www.antwerpdiamondhouse.be/"
        return true;
}


function RemoveComma(str)
{
        
        var NewStr = ""
        var temp = ""

        j=str.length
        
        for(i=0; i<=j-1; i++)
        {
                temp = str.slice(i, i+1)
                if (temp != ",")
                {
                        NewStr = NewStr + temp
                }
                        
        }
        
        return (NewStr)
}       
/* this function returs the date is valid or not
For proper working of this function you should pass integer values
If the values are blanks then pass zero to all three parameters
*/
function IsValidDate(month,day,year)
{
        //alert("month=" + month + "; day=" + day + "; Year=" + year)
        if ((month < 1) || (month > 12))
                return(false)
        if ((day < 1) || (day > 31))
                return(false)
        if (year < 1)
                return(false)
                
        var maxdays = new Array()
        
        maxdays[0] = 31         //jan
        maxdays[1] = 28         //feb
        maxdays[2] = 31         //mar
        maxdays[3] = 30         //apr
        maxdays[4] = 31         //may
        maxdays[5] = 30         //jun
        maxdays[6] = 31         //jul
        maxdays[7] = 31         //aug
        maxdays[8] = 30         //sep
        maxdays[9] = 31         //oct
        maxdays[10] = 30        //nov
        maxdays[11] = 31        //dec
        
        if (month != 2) 
        {
                if (day > maxdays[month-1])
                        return (false)
        }
        else
        {
                if (year % 4 != 0)
                {
                        if( day > 28)
                                return (false)
                }
                else
                {
                        if( day > 29)
                                return (false)
                }
        }
        return (true)
}

/* Email validation function */
function emailCheck (emailStr) {

var emailPat=/^(.+)@(.+)$/
var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]"
var validChars="\[^\\s" + specialChars + "\]"
var quotedUser="(\"[^\"]*\")"
var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/
var atom=validChars + '+'
var word="(" + atom + "|" + quotedUser + ")"
var userPat=new RegExp("^" + word + "(\\." + word + ")*$")
var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$")
var matchArray=emailStr.match(emailPat)

if (matchArray==null) {
 //     alert("Email address seems incorrect (check @ and .'s)")
        return false
}
var user=matchArray[1]
var domain=matchArray[2]

// See if "user" is valid 
if (user.match(userPat)==null) {
   // alert("The username doesn't seem to be valid.")
    return false
}

var IPArray=domain.match(ipDomainPat)
if (IPArray!=null) {
    // this is an IP address
          for (var i=1;i<=4;i++) {
            if (IPArray[i]>255) {
                //alert("Destination IP address is invalid!")
                return false
            }
    }
    return true
}

// Domain is symbolic name
var domainArray=domain.match(domainPat)
if (domainArray==null) {
        //alert("The domain name doesn't seem to be valid.")
    return false
}

var atomPat=new RegExp(atom,"g")
var domArr=domain.match(atomPat)
var len=domArr.length
if (domArr[domArr.length-1].length<2 || 
    domArr[domArr.length-1].length>3) {
   //alert("The Email-address must end in a three-letter domain, or two letter country.")
   return false
}

// Make sure there's a host name preceding the domain.
if (len<2) {
   //var errStr="This Email-address is missing a hostname!"
   //alert(errStr)
   return false
}

return true;
}

/* check Zipcode */
function IsValidateZip(field) {
var valid = "0123456789-+qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM";
var hyphencount = 0;

if (field.length!=4 && field.length!=10) {
//alert("Please enter your proper zip / post code.");
return false;
}
for (var i=0; i < field.length; i++) {
temp = "" + field.substring(i, i+1);
if (temp == "-") hyphencount++;
if (valid.indexOf(temp) == "-1") {
return false;
}
if ((hyphencount > 1) || ((field.length==10) && ""+field.charAt(4)!="-")) {
return false;
   }
}
return true;
}

/* check phone */
function IsValidPhone(field) {
var valid = "0123456789-+";
var hyphencount = 0;

if ((field.length<=4) || (field.length>=16)) {
return false;
}
for (var i=0; i < field.length; i++) {
temp = "" + field.substring(i, i+1);
if (temp == "-") hyphencount++;
if (valid.indexOf(temp) == "-1") {
return false;
}
}
return true;
}





        <!--
        
        
        function FormSubmit(ElementValue)
        {
        if (ElementValue=='continue')
                        if (Validate()!=true)
                                return
                                
                document.recapform.FormAction.value = ElementValue;
                document.recapform.submit();
        }
        
        function Validate()
        {
                var msg
                var empty_fields = ""

                                     
        if (IsValidChars(document.recapform.F1.value)==false)
                empty_fields += "\n          " + "*   First Name"
        if (IsValidChars(document.recapform.L1.value)==false)
                empty_fields += "\n          " + "*   Last Name"
        if (IsValidChars(document.recapform.Company.value)==false)
                empty_fields += "\n          " + "*   Company"
        if (emailCheck(document.recapform.Email.value)==false)
                empty_fields += "\n          " + "*   E-mail address"
        if (IsValidChars(document.recapform.S1.value)==false)
                empty_fields += "\n          " + "*   Mailing Address"
        if (IsValidChars(document.recapform.C2.value)==false)
                empty_fields += "\n          " + "*   City"
        if (IsValidChars(document.recapform.Z1.value)==false)
                empty_fields += "\n          " + "*   Zip/Postal Code"
        if (document.recapform.C3.selectedIndex==0)
                empty_fields += "\n          " + "*   Country"                
       Dayphone = document.recapform.P2A.value + document.recapform.P2E.value + document.recapform.P2.value
         
        if (IsValidPhone(Dayphone)==false) 
                empty_fields += "\n          " + "*   Day time phone"

              
        if (empty_fields) 
                {
                        msg  = "______________________________________________________\n\n"
                        msg += "Please correct the following error(s) and then submit the form.\n"
                        msg += "______________________________________________________\n\n"
                        
                    msg += "- The following required field(s) are empty or invalid:" 
                            + empty_fields + "\n"
                        alert(msg)
                        return false
                }
                else
                {
                        return true
                }
        }
        
        //-->