javascript input validations (client side)

validate.js

// function to get only numbers in input field
function validateKeyStrokes(event) {
    var charCode = (event.which) ? event.which : event.keyCode;
    if (charCode > 31 && (charCode < 48 || charCode > 57)) {
        return false;
    }
    return true;
}
// use like this onkeypress="return validateKeyStrokes(event)"

// function to get only text in input field
function onlyAlphabets(e, t) {
    try {
        if (window.event) {
            var charCode = window.event.keyCode;
        }
        else if (e) {
            var charCode = e.which;
        }
        else { return true; }
        if ((charCode > 64 && charCode < 91) || (charCode > 96 && charCode < 123))
            return true;
        else
            return false;
    }
    catch (err) {
        alert(err.Description);
    }
}
// use like this onkeypress="return onlyAlphabets(event, this)"