function switchplate(obj) {
var form = document.getElementById('selector');
if (obj) { untickall(form, obj) };

var insert = getFormValueByName(form, 'insert');
var cover = getFormValueByName(form, 'cover');

var imagename;
if (insert==null) { }
else if (cover==null) { imagename = insert; }
else { imagename = insert+"_"+cover; }

if (imagename!=null) { document.getElementById(imagename).style.display='block'; }
hideallimages(imagename);
//alert(imagename)

}

function hideallimages(imagename) {
	var images = document.getElementsByTagName('img');
	for (var i = 0; i < images.length; i++ ) {
		if (images[i].id != imagename && images[i].className == 'socket') {
			images[i].style.display='none';
		}
	}
}

function getFormValueByName(form, name) { 
	for (var i = 0; i < form.elements.length; i++ ) {
			if (form.elements[i].type == 'checkbox') {
				if (form.elements[i].name == name && form.elements[i].checked == true) {
					return form.elements[i].value;
					i=9999999;
				}
			}
	}
}


function untickall(form, obj) {
	for (var i = 0; i < form.elements.length; i++ ) {
			if (form.elements[i].type == 'checkbox') {
				if (form.elements[i].name == obj.name && form.elements[i].value != obj.value) {
					form.elements[i].checked = false;
				} else if (obj.name == 'insert' && form.elements[i].name == 'insert' && form.elements[i].value == obj.value) {
					form.elements[i].checked = true;
				}
			}
	}
}