Validate Email - No under score or @ after first @

<script  type="text/javascript"> 

function  fn_Email_Check(Chartocheck) {

var  rx = /^([A-Za-z0-9_\\-\\.])+\\@([A-Za-z0-9\\-\\.]+[^_@])+\\.([A-Za-z]{2,4})$/;

if  (rx.test(Chartocheck) == false )

return  false ;

else 

return  true ;

}

</script>