var gender = "male"
image_on = new Image;
image_on.src = 'images/radio_on.gif';
image_off = new Image;
image_off.src = 'images/radio_off.gif';

function changeGender(myGender,myForm) {
	
	gender = myGender.name;
	if (gender == 'male') {
		document.male.src = image_on.src;
		document.female.src = image_off.src;
	} else if (gender == 'female') {
		document.male.src = image_off.src;
		document.female.src = image_on.src;
	}
	document.signup.gender_value.value = gender;
}