function validatestring(src,reg)
{
    var regex=new RegExp("[" + reg + "]","i");
    return regex.test(src);
}


function testemail(src)
{
     var emailReg = "^[\\w-_\.]*[\\w-_\.]\@[\\w]\.+[\\w]+[\\w]$";
     var regex = new RegExp(emailReg);
     return regex.test(src);
}

function isEmailAddr(email)
{ var result = false
  var theStr = new String(email)
  var index = theStr.indexOf("@");

  if (index > 0){
    var pindex = theStr.indexOf(".",index);
    if ((pindex > index+1) && (theStr.length > pindex+1))
	result = true; }
  return result;}

function isvalid(form,field) 
{
if (field.value != ""){
	var mess = ""
	if (!isEmailAddr(field.value)){mess = mess + "You must indicate a valid email address (check format).\n";}
	if (mess){alert(mess);return false; }}
}