//Define global variables
        var layerNumShowing=5;
		//browser and proprietary stuff
        function init(){
          
						//layerStyleRef="layer.style.";
						//layerRef="document.getElementById('portframe').contentDocument.getElementById(";   
						//styleSwitch=").style";
						
						layerStyleRef="layer.style.";
						layerRef="document.getElementById(";   
						styleSwitch=").style";

						}

init()
		// layers show and hide
function showLayerNumber(number)
{
     var layerNumToShow=number;
     hideLayer(eval('"title' + layerNumShowing+'"'));
     showLayer(eval('"title' + layerNumToShow+'"'));
     layerNumShowing=layerNumToShow;        

}
                
        
function showLayer(layerName)
{
     eval(layerRef+'"'+layerName+'"'+styleSwitch+'.visibility="visible"');         
	
}       

function hideLayer(layerName)
{
    eval(layerRef+'"'+layerName+'"'+styleSwitch+'.visibility="hidden"');  

}