function showlayer(layerName)  
	{ 
	document.getElementById(layerName).style.display='block';  
	}
function hidelayer(layerName)  
	{ 
	document.getElementById(layerName).style.display='none';  
	}

function changecolor(layerName)  
	{ 
	document.getElementById(layerName).style.color='#fff'; 
	document.getElementById(layerName).style.cursor='default'; 
	}
function changecolorback(layerName)  
	{ 
	document.getElementById(layerName).style.color='#000';
	document.getElementById(layerName).style.cursor='auto';  
	}