JS :: Simple form validation

form_validation.js

function validate(f,v,a,x){ 
	for(a=0;x=f[a++];) 
		if((v=window[x.getAttribute('valid')])&&!v(x.value)){
			alert(x.getAttribute('alert'));
			return !x.focus();
		}
}
function notempty(x){return x>''}
function ismail(e){return /^[\w\.-]{2,}@[\w\.-]+\.[a-z]{2,5}$/i.test(e)}

// <form onsubmit="return validate()">
// <input valid="notempty" alert="enter name!" type="text" name="name">
// <input valid="isemail" alert="enter email!" type="text" name="email">
// </form>