function checkform(obj) {
	if(isEmail(obj.Email.value)==false) {
		alert('Please enter a valid email address.');
		return false;
	} else {
		return true;
	}			

}
function isEmail(m) {
	if ((m == '') || (m == ' ')) { return false; }
    var a = 1;var ml = m.length;
    while ((a < ml) && (m.charAt(a) != "@")) { a++ }
    if ((a >= ml) || (m.charAt(a) != "@")) {return false;} else {a = a + 2;}
    while ((ml > a) && (m.charAt(a) != ".")) { a++ }
    if ((a >= ml - 1) || (m.charAt(a) != ".")) {return false;} else {return true;}
}