Regular Expression: Allow letters, numbers, and spaces (with at least one letter or number)

Question

I\'m currently using this regex ^[A-Z0-9 _]*$ to accept letters, numbers, spaces and underscores. I need to modify it to require at least one number or letter s

Answer 1

$("#ValuationName").bind("keypress", function (event) {
    if (event.charCode!=0) {
        var regex = new RegExp("^[a-zA-Z ]+$");
        var key = String.fromCharCode(!event.charCode ? event.which : event.charCode);
        if (!regex.test(key)) {
            event.preventDefault();
            return false;
        }
    }
});