function trim(s)

 {

    if(s!="")  return s.replace(/^\s*(.+?)\s*$/, "$1");

    else       return "";

 }







 function CheckEmail(str)

     {

        var email = /^[0-9a-z]([-_\.:]?[0-9a-z])*@[0-9a-z]([-_\.]?[0-9a-z])*\.[a-z]{2,4}$/i;

        if (email.test(str))  return true; 

        else return false;

     }