Phone Number Actual Validation

by Hiroshi on June 15, 2008

in Form, Form Validation

In forms to prevent people from writing jhgkljtb7ibylihyb8lyi in phone TextField use the following script.

Head Section Code

Use this javascript in head section of your webpage. Or use external javasript file.

<script language = "Javascript">
// 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 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){
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>

Form Code

<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>

Download Phone Number Validation Script

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