function nl_blur(field){
    var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
    if (!filter.test(field.value))
    //if(field.value.search(/^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$/)==-1)
    {return false;}
    else
    return true;
}
function nl_submit(sform){if(!nl_blur(sform.email))
{alert('Please enter valid email address');sform.email.focus();return false;}
else
{sform.submit();}}