function add_value (x) {

	document.make.sendnothing.checked = false;

	if (document.make.donation.value == '') {
		document.make.donation.value = x;
	} else {
		document.make.donation.value += '+'; 
		document.make.donation.value += x; 
	}
	var userinput = document.make.donation.value;
	                document.make.donation.value = eval(userinput);
}

function sub_value (x) {
	if     (document.make.donation.value == '') {
		document.make.donation.value = 0;
	} else {
		document.make.donation.value += '-';
		document.make.donation.value += x;
	}
	var userinput = document.make.donation.value;
	                document.make.donation.value = eval(userinput);

	if (	document.make.healthDVD.checked  == false &&
		document.make.healthVHS.checked  == false &&
		document.make.stepsDVD.checked   == false &&
		document.make.stepsVHS.checked   == false &&
		document.make.sermonsDVD.checked == false &&
		document.make.sermonsVHS.checked == false ) {
			document.make.sendnothing.checked = true;
	}

}

function Send_Nothing() {
	if (document.make.sendnothing.checked) {
		document.make.donation.value     = '0';
		document.make.healthDVD.checked  = false;
		document.make.healthVHS.checked  = false;
		document.make.stepsDVD.checked   = false;
		document.make.stepsVHS.checked   = false;
		document.make.sermonsDVD.checked = false;
		document.make.sermonsVHS.checked = false;
	}
}

function healthDVD_donation(x) {
	if (document.make.healthDVD.checked)  { add_value (x); } 
	else 				      { sub_value (x); }
}

function healthVHS_donation(x) {
	if (document.make.healthVHS.checked)  { add_value (x); } 
	else 				      { sub_value (x); }
}

function stepsDVD_donation(x) {
	if (document.make.stepsDVD.checked)   { add_value (x); }  
	else				      { sub_value (x); }
}

function stepsVHS_donation(x) {
	if (document.make.stepsVHS.checked)   { add_value (x); }  
	else				      { sub_value (x); }
}

function sermonsDVD_donation(x) {
	if (document.make.sermonsDVD.checked) { add_value (x); }  
	else				      { sub_value (x); }
}

function sermonsVHS_donation(x) {
	if (document.make.sermonsVHS.checked) { add_value (x); }  
	else				      { sub_value (x); }
}

function valid_email(ss,msg) {
	if ( (ss == "") || (ss.indexOf(" ") != -1) || (ss.indexOf("@") < 1) ){
		alert(msg);
		return false;
	}
	return true;
}

function valid_form_info(ss,msg) {
	if ( (ss == "") || (ss.indexOf("@") > 0) ){
		alert(msg);
		return false;
	}
	return true;
}


function validate_info(){
	with ( document.make ) {

		if ( !valid_form_info(name.value,"Please enter a valid NAME.") ){ return false; }

		if ( !valid_form_info(address.value,"Please enter a valid ADDRESS.") ){ return false; }

		if ( !valid_form_info(city.value,"Please enter a valid CITY.") ){ return false; }

		if ( !valid_form_info(state.value,"Please enter a valid STATE.") ){ return false; }

		if ( !valid_form_info(zip.value,"Please enter a valid ZIP CODE.") ){ return false; }

		if ( !valid_form_info(phone.value,"Please enter a valid PHONE NUMBER.") ){ return false; }

		if ( !valid_email(email.value,"Please enter a valid EMAIL ADDRESS") ){ return false; }

		if ( donation.value <= 0 ) {
			alert("You must enter a Donation Amount before you can continue.");
			return false;
		}

		return true;
	} //with statement
} //validate_info function