Email validation using javascript

function validateEmail()

{

//name of email input field

obj=document.getElementById(‘txtEmail’);

msg=”Please enter valid email address”;
var emailStr = /^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z]
[a-zA-Z\.]*[a-zA-Z]$/;
if (emailStr.test(obj.value) == false)

{
alert(msg);
obj.focus();
obj.select();
return false;
}
return true;
}