Javascript: Check text format

javascript.js

// Function 1, return true or false.
(/^[a-zA-Z0-9\.\_\-]*$/g.test(document.getElementById("id").value)

// Function 2, return 0 is normal.
document.getElementById("id").value.search(/[^0-9_]/)

//Check Email Format, return 0 is error.
// Rules: 1. Just 1 '@'
//        2. At least one '.' in the URL and can't 1 by 1
//        3. No space
var regExp =/^[^@^\s]+@[^\.@^\s]+(\.[^\.@^\s]+)+$/;docu
ment.getElementById("sener").vlue.match(regExp);