function checkData (){
	if (document.tellFriend.senderName.value == "") {
	alert("Please enter your name.")
	document.tellFriend.senderName.focus()
	return false}
	if (document.tellFriend.senderEmail.value.indexOf("@") == -1 || document.tellFriend.senderEmail.value.indexOf("@") == 1 || document.tellFriend.senderEmail.value.indexOf(".") == 0 || document.tellFriend.senderEmail.value.indexOf(".") == -1) {
	alert("Please enter your e-mail address.")
	document.tellFriend.senderEmail.focus()
	return false}
	 if (document.tellFriend.friendName.value == "") {
	alert("Please enter your friend's name.")
	document.tellFriend.friendName.focus()
	return false}
	if (document.tellFriend.friendEmail.value.indexOf("@") == -1 || document.tellFriend.friendEmail.value.indexOf("@") == 1 || document.tellFriend.friendEmail.value.indexOf(".") == 0 || document.tellFriend.friendEmail.value.indexOf(".") == -1) {
	alert("Please enter a friend's e-mail address.")
	document.tellFriend.friendEmail.focus()
	return false}
}