How to prevent user from entering special characters in text box when length is 0?

Question

I have the following code which prevents user from entering space when the length is 0. Now, how can I prevent user from entering all special characters(anything other than

Answer 1

This is what you are looking for:

$('#DivisionName').bind('keypress', function(e) {

    if($('#DivisionName').val().length == 0){
        var k = e.which;
        var ok = k >= 65 && k <= 90 || // A-Z
            k >= 97 && k <= 122 || // a-z
            k >= 48 && k <= 57; // 0-9

        if (!ok){
            e.preventDefault();
        }
    }
}); 

or see here: http://jsfiddle.net/D4dcg/