Javascript Function for Validation on Input fields ( Useful for Number,Letters,Characters,Currency validations)

Hi Guys,

Many a times we have requirement where we need to have validation on Input field to let user enter  just number, just letters or related to currency etc.

Below you can find a single javascript function to handle all situation related to numbers, characters, currency, specialCharacters.

Javascript code:

  <script type="text/javascript">
    // This function is being used for providing different validation on your text box as per your need
    function inputLimiter(e,allow) {
            var AllowableCharacters = '';

            if (allow == 'Letters'){AllowableCharacters=' ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';}
            if (allow == 'Numbers'){AllowableCharacters='1234567890';}
            if (allow == 'NameCharacters'){AllowableCharacters=' ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-.\'';}
            if (allow == 'NameCharactersAndNumbers'){AllowableCharacters='1234567890 ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-\'';}
            if (allow == 'Currency'){AllowableCharacters='1234567890.';}

            var k = document.all?parseInt(e.keyCode): parseInt(e.which);
            if (k!=13 && k!=8 && k!=0){
                if ((e.ctrlKey==false) && (e.altKey==false)) {
                return (AllowableCharacters.indexOf(String.fromCharCode(k))!=-1);
                } else {
                return true;
                }
            } else {
                return true;
            }
        }
    </script>

Just call the above function onKeyPress of input field and pass Argument as per your requirement.

For ex: 

1) Limit users to enter only number:
onkeypress="return inputLimiter(event,'Numbers');"

2) Restrict user to enter only characters (both small and Caps)
onkeypress="return inputLimiter(event,'Letters');"

3) Restrict user to enter just currency (with decimals)
onkeypress="return inputLimiter(event,'Currency');"

4) Restrict user to enter characters and numbers
onkeypress="return inputLimiter(event,'NameCharactersAndNumbers');"

5) Restrict user to enter Name Characters only (i.e. with - and . between names)
onkeypress="return inputLimiter(event,'NameCharacters');"