validation - Validating email and password using javascript -

i know use serverside validation security, except head around validation.

my efforts far have amounted following

function validateuser() {     var x=document.forms["myform"]["email"].value;     var y=document.forms["myform"]["password"].value;     var atpos=x.indexof("@");     var dotpos=x.lastindexof(".");     var uppercase = password.match(/[a-z]/)     var lowercase = password.match(/[a-z]/g)     var number = password.match(/[0-9]/g)     if (atpos<1 || dotpos<atpos+2 || dotpos+2>=x.length)     {     alert("not valid e-mail address or password");     return false;     }else{      alert("valid email address , password");     return true;      }     } 

basically, need alert box pop when password doesn't have @ least 1 lowercase, uppercase , number. far code throwing error when email in wrong format. add if statement check password characters?

thanks in advance,

james

few issues have in current implementation:

a. error you're getting password undefined.

right you're doing:

var y=document.forms["myform"]["password"].value; 

but refer "password" further on:

var uppercase = password.match(/[a-z]/) var lowercase = password.match(/[a-z]/g) 

change var y to:

var password=document.forms["myform"]["password"].value; 

b. validate email, should use regex such as:

var re = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-za-z\-0-9]+\.)+[a-za-z]{2,}))$/;  var isvalidemail = re.test(email); 

c. check password rules, should rely on regular expressions have in place (and strip out atpos, dotpos usage - makes more complicated needs be).

example:

var email='me@mailinator.com'; var password='test-p1assword'; var hasupper = password.match(/[a-z]/) var haslower = password.match(/[a-z]/g) var hasnumber = password.match(/[0-9]/g)  var re = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-za-z\-0-9]+\.)+[a-za-z]{2,}))$/;  var isvalidemail = re.test(email);  if (isvalidemail && hasupper && haslower && hasnumber) {     alert("valid email address , password");     return true; } else {      alert("not valid e-mail address or password");     return false; } 

jsfiddle example, complete regex validate email , password: http://jsfiddle.net/4hh3t/2/

the regex taken from: validate email address in javascript?