function viewLayerByCheckbox(el,layer_name){
	alert('dfgdfg');
	if(el.checked){
		document.getElementById(layer_name).style.display = 'block';
	}else{
		document.getElementById(layer_name).style.display = 'none';
	}	
	
}


function viewLayer(layer_name){
	
	var lay =  document.getElementById(layer_name);
	if(lay.getAttribute('timer_id')){
		clearTimeout(lay.getAttribute('timer_id'));
	}
	lay.style.display = 'block';		
	
}
function hideLayer(layer_name){
	id = setTimeout(function() {document.getElementById(layer_name).style.display = 'none';},200);
	document.getElementById(layer_name).setAttribute('timer_id', id);
}
function hideLayerWithoutTimer(layer_name){
	document.getElementById(layer_name).style.display = 'none';
	document.getElementById(layer_name).setAttribute('timer_id', '');
}