function CheckCardNumber(form) {
		if (form.amount.value.length == 0 || !form.amount.value.toString().match(/^[-]?\d*\.?\d*$/)) { // Verify donation is not empty or letters
				alert("Please enter a valid donation amount.");
				form.amount.focus();
				return false;
		}

		if (!form.CardNumber.value.toString().match(/^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|6(?:011|5[0-9][0-9])[0-9]{12}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|(?:2131|1800|35\d{3})\d{11})$/)) { // Verify card is valid format
				alert("Please enter a valid card number.");
				form.CardNumber.focus();
				return false;
		}

		if (form.ExpMon.value.length != 2) { // Verify month is 2 digits
				alert("Please enter the expiration month.");
				form.ExpMon.focus();
				return false;
		}
		
		if (form.ExpYear.value.length != 2) { // Verify year is 2 digits
				alert("Please enter the expiration year.");
				form.ExpYear.focus();
				return false;
		}
		
		if (form.cvv2_number.value.length < 3) { // Verify CCV is at least 3 digits
				alert("Please enter a valid CCV.");
				form.cvv2_number.focus();
				return false;
		}
		
		if (form.first_name.value.length == 0) { // Verify first name is not empty
				alert("Please enter your first name.");
				form.first_name.focus();
				return false;
		}
		
		if (form.last_name.value.length == 0) { // Verify last name is not empty
				alert("Please enter your last name.");
				form.last_name.focus();
				return false;
		}
		
		if (form.city.value.length == 0) { // Verify city is not empty
				alert("Please enter a valid city.");
				form.city.focus();
				return false;
		}
		
		if (form.zip.value.length != 5) { // Verify zip code is 5 digits
				alert("Please enter a valid  5 digit zip code.");
				form.zip.focus();
				return false;
		}
		
		if (form.PhoneNumber.value.length < 10) { // Verify phone number is at least 10 digits
				alert("Please enter a valid phone number with area code.");
				form.PhoneNumber.focus();
				return false;
		}
		
		if (form.email.value.length < 6) {
				alert("Please enter a valid email address.");
				form.email.focus();
				return false;
		}
}