Block Special Characters while Typing

block.js

function RestrictSpaceSpecial(e) {
    var exp = String.fromCharCode(window.event.keyCode)
        //Below line will have the special characters that is not allowed you can add if you want more for some characters you need to add escape sequence
    var r = new RegExp(/^[a-zA-Z0-9-_]+$/);
    if (exp.match(r)) {
        return true;
    } else {
        window.event.keyCode = 0
        return false;
    }
}

// onkeypress="javascript:return RestrictSpaceSpecial(event);"