function validateGuestBookForm(){
	var Regex = new RegExp("^([a-zA-Z0-9])+(.[a-zA-Z0-9_])*@([a-zA-Z0-9-_])+.[A-Za-z]{2,4}(.[A-Za-z]{2,4})*$");
	if(document.guestBookEntryForm.name.value.length<4 || document.guestBookEntryForm.name.value.length>100) {
		alert("Name should be between 4 to 100 characters.");
		return false;
	}
	else if(document.guestBookEntryForm.email.value.length>100) {
		alert("Email address should not exceed 100 characters.");
		return false;
	}
	else if((!Regex.test(document.guestBookEntryForm.email.value)) && document.guestBookEntryForm.email.value.length!=0) {
		alert("Invalid format of email address.");
		return false;
	}
	else if(document.guestBookEntryForm.comment.value.length<5) {
		alert("Comment should contain atleast 5 characters.");
		return false;
	}
	else if(document.guestBookEntryForm.suggestion.value.length<5) {
		alert("Suggestion should contain atleast 5 characters.");
		return false;
	}
	return true;
}