var D = 'none';
var E = 'none';

function changeDisplay()
{
	if(document.styleSheets[0].cssRules) // FF
	{
		ObjStyle = document.getElementById('MyStyles').sheet.cssRules[0].style; 
		ObjStyleE = document.getElementById('MyStyles').sheet.cssRules[1].style; 
	} else {
		ObjStyle = document.getElementById('MyStyles').styleSheet.rules[0].style; 
		ObjStyleE = document.getElementById('MyStyles').styleSheet.rules[1].style; 
	}
	
	D = ObjStyle.display;  
	E = ObjStyleE.display;  
	
	if (D=='none')
	{
		D=''; 
		E='none';
	} else {
		D='none';
		E='';
	}
	ObjStyle.display = D; 
	ObjStyleE.display = E;
}