function checkemail(source, arguments)
{
  var objValue = arguments.Value;
  objValue = Trim(objValue);
  var userPat = /^[\w-\'\.]{1,}\@([\da-zA-Z-]{1,}\.){1,}[\da-zA-Z-]{2,7}(;[ ]?[\w-\'\.]{1,}\@([\da-zA-Z-]{1,}\.){1,}[\da-zA-Z-]{2,7})*$/;
  if (userPat.test(objValue)) {
      arguments.IsValid = true;
  }

  else {
      arguments.IsValid = false;
  }

}

function LTrim ( value ) {
    var re = /\s*((\S+\s*)*)/;
    return value.replace(re, "$1");
}

function RTrim ( value ) {
    var re = /((\s*\S+)*)\s*/;
    return value.replace(re, "$1");
}

function Trim( value ) {
    return LTrim(RTrim(value));
}