function checkmail(s)
{
  var atpos;
  var ok;
  var i;
  var tldpos;
  var tldnum;
  var rtnok = 0;
  
  //x@y.z  is minimum nescessary format  

  if ((s.indexOf("@") != -1) && (s.indexOf(".") != -1)){
  
    atpos = s.indexOf("@");
    if (atpos  > 0) {
      rtnok = 1;
    }     //pass test1

    ok = 0;
    i = 0;
    while ((!ok) && (i<tld.length)) {
      tldpos = s.indexOf(tld[i]);
      if (tldpos != -1) {
        ok = 1;
        tldnum = i;
      }
      i++;
    }  
  
    rtnok = rtnok && ok;       //pass test2
    rtnok = rtnok && ((tldpos - atpos) > 1);     //pass test3
  }
  
  return (rtnok);
}