var rollover_superDuperPreLoad = '';

	function rollover_PreLoad() 
		{
		rollover_PreLoadImage('cobConstructionOn',						'images/cobNavConstructionStagesOn.jpg');
		rollover_PreLoadImage('cobConstructionOff',						'images/cobNavConstructionStages.jpg');		
		
		rollover_PreLoadImage('cobBuildingsOn',							'images/cobNavBuildingsOn.jpg');
		rollover_PreLoadImage('cobBuildingsOff',						'images/cobNavBuildings.jpg');
		
		rollover_PreLoadImage('cobPorchesOn',							'images/cobNavPorchesOn.jpg');
		rollover_PreLoadImage('cobPorchesOff',							'images/cobNavPorches.jpg');
					
		rollover_PreLoadImage('cobRoofOn',  							'images/cobNavRoofTrussesOn.jpg');
		rollover_PreLoadImage('cobRoofOff', 							'images/cobNavRoofTrusses.jpg');		
		
		rollover_PreLoadImage('cobJoineryOn',  							'images/cobNavJoineryOn.jpg');
		rollover_PreLoadImage('cobJoineryOff', 							'images/cobNavJoinery.jpg');
										
		rollover_superDuperPreLoad = 'finished';
		}
		
	function rollover_PreLoadImage(imgObj,imgSrc) 
		{
		if (document.images) 
			{
			eval(imgObj + ' = new Image()');
			eval(imgObj + '.src = "' + imgSrc +'"');
			}
		}

	function rollover_changeImage(imgName,imgObj) 
		{
		 if (rollover_superDuperPreLoad == 'finished') 
			{
			if ((document.images[imgName]) && (imgObj)) 
				{
				document.images[imgName].src = eval(imgObj + ".src");
				}
			}
		}