function formCheck() {
   Error = false;

        if (document.form.Name_1.value == "") {
      			alert("Please fill in your friend's name.");
                document.form.Name_1.focus();
      			Error = true;
   		}
	else if (document.form.Email_1.value == "") {
      			alert("Please fill in your friend's email address.");
                document.form.Email_1.focus();
      			Error = true;
   		}

		else if(isValidEmail(document.form.Email_1) == false) {
      			alert("Please check that you have entered a valid email address.");
      			document.form.Email_1.focus();
      			Error = true;
   		}

	else if (document.form.Sender_FirstName.value == "") {
      			alert("Please fill in your first name.");
                document.form.Sender_FirstName.focus();
      			Error = true;
   		}
	else if (document.form.Sender_LastName.value == "") {
      			alert("Please fill in your last name.");
                document.form.Sender_LastName.focus();
      			Error = true;
   		}


	else if (document.form.Sender_Email.value == "") {
      			alert("Please fill in your email address.");
                document.form.Sender_Email.focus();
      			Error = true;
   		}

		else if(isValidEmail(document.form.Sender_Email) == false) {
      			alert("Please check that you have entered a valid email address.");
      			document.form.Sender_Email.focus();
      			Error = true;
   		}

else if (document.form.Message.value == "") {
      			alert("Please fill in your email message.");
                document.form.Message.focus();
      			Error = true;
   		}


        if (Error == true) {
                return false;
        }
        else {
                return true;
        }

}


function isValidEmail(theField) {

   if(theField.value.indexOf('@', 0) == -1)
      return false;
   else
   if (theField.value.indexOf("@") >= theField.value.lastIndexOf("."))
      return false;
   else
   if (theField.value.length == (theField.value.lastIndexOf(".") + 1))
      return false;
   else
      return true;
}