//定义是否有选中菜单 oLastMenu
var oLastMenu = null;
function ChangeView( objID )
{
	var obj = document.getElementById( objID );
	if( !obj ) return;
	if( obj.style.display == 'none' )
	{
		if( oLastMenu && oLastMenu != obj )
		{
			oLastMenu.style.display = 'none';
		}
			
		obj.style.display = 'block';
		//执行一次后出现选中菜单
		oLastMenu = obj;
	}

}

function OverView( obj )
{
		oLastMenu=obj
}