Phone Number Validation
<html>
<script language = "Javascript">
/**
* DHTML phone number validation script. Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/)
*/
// Declaring required variables
var digits = "0123456789";
// non-digit characters which are allowed in phone numbers
var phoneNumberDelimiters = "()- ";
// characters which are allowed in international phone numbers
// (a leading + is OK)
var validWorldPhoneChars = phoneNumberDelimiters + "+";
// Minimum no of digits in an international phone no.
var minDigitsInIPhoneNumber = 10;
function isInteger(s)
{ var i;
for (i = 0; i < s.length; i++)
{
// Check that current character is number.
var c = s.charAt(i);
if (((c < "0") || (c > "9"))) return false;
}
// All characters are numbers.
return true;
}
function trim(s)
{ var i;
var returnString = "";
// Search through string's characters one by one.
// If character is not a whitespace, append to returnString.
for (i = 0; i < s.length; i++)
{
// Check that current character isn't whitespace.
var c = s.charAt(i);
if (c != " ") returnString += c;
}
return returnString;
}
function stripCharsInBag(s, bag)
{ var i;
var returnString = "";
// Search through string's characters one by one.
// If character is not in bag, append to returnString.
for (i = 0; i < s.length; i++)
{
// Check that current character isn't whitespace.
var c = s.charAt(i);
if (bag.indexOf(c) == -1) returnString += c;
}
return returnString;
}
function checkInternationalPhone(strPhone){
var bracket=3
strPhone=trim(strPhone)
if(strPhone.indexOf("+")>1) return false
if(strPhone.indexOf("-")!=-1)bracket=bracket+1
if(strPhone.indexOf("(")!=-1 && strPhone.indexOf("(")>bracket)return false
var brchr=strPhone.indexOf("(")
if(strPhone.indexOf("(")!=-1 && strPhone.charAt(brchr+2)!=")")return false
if(strPhone.indexOf("(")==-1 && strPhone.indexOf(")")!=-1)return false
s=stripCharsInBag(strPhone,validWorldPhoneChars);
return (isInteger(s) && s.length >= minDigitsInIPhoneNumber);
}
function ValidateForm(){
var Phone=document.frmSample.txtPhone
if ((Phone.value==null)||(Phone.value=="")){
alert("Please Enter your Phone Number")
Phone.focus()
return false
}
if (checkInternationalPhone(Phone.value)==false){
alert("Please Enter a Valid Phone Number")
Phone.value=""
Phone.focus()
return false
}
return true
}
</script
<body>
<form name="frmSample" method="post" action="#" onSubmit="return ValidateForm()">
<p>Enter a phone number :
<input type="text" name="txtPhone">
</p>
<p>
<input type="submit" name="Submit" value="Submit">
</p>
</form
</body>
</html>
