//------------------------------------------------------------------------
function layerHabilitado(layerName, nav)
{
   if(nav == "nav2" || nav == "nav3" || nav == "nav4") return eval("document.layers."+layerName+".visibility == 'show'");
   else if(nav == "ie3" || nav == "ie4") return eval(layerName+"caixaVazio.style.visibility == 'visible'");
   else if(nav == "ie5" || nav == "ie6" || nav == "nav6") return eval(document.getElementById(layerName)+".style.visibility == 'visible'");
}
//------------------------------------------------------------------------
function habilitaLayer(layerName, nav)
{
   if(nav == "nav2" || nav == "nav3" || nav == "nav4") eval("document.layers."+layerName+".visibility = 'show'");
   else if(nav == "ie3" || nav == "ie4") eval(layerName+".style.visibility = 'visible'");
   else if(nav == "ie5" || nav == "ie6" || nav == "nav6") document.getElementById(layerName).style.visibility = 'visible';
}
//------------------------------------------------------------------------
function desabilitaLayer(layerName, nav)
{
    if(nav == "nav2" || nav == "nav3" || nav == "nav4") eval("document.layers."+layerName+".visibility = 'hide'");
    else if(nav == "ie3" || nav == "ie4") eval(layerName+".style.visibility = 'hidden'");
    else if(nav == "ie5" || nav == "ie6" || nav == "nav6") document.getElementById(layerName).style.visibility = 'hidden';	
}
//------------------------------------------------------------------------
// Operadores (=, -=, +=)
function moveLayer(layerName, top, left, operador, nav)
{	
	if(nav == "nav2" || nav == "nav3" || nav == "nav4") {
		if (top != '') eval("document.layers."+layerName+".top "+ operador + " " + top);
		if (left != '') eval("document.layers."+layerName+".left "+ operador + " " + left);	
	}	
	else if(nav == "ie3" || nav == "ie4") { 
		if (top != '') eval(layerName+".style.pixelTop "+ operador + " " + top);
		if (left != '') eval(layerName+".style.pixelLeft "+ operador + " " + left);		
	}
	else if(nav == "ie5" || nav == "ie6") { 
		if (top != '') eval("document.getElementById('"+layerName+"').style.pixelTop "+ operador + " " + top);
		if (left != '') eval("document.getElementById('"+layerName+"').style.pixelLeft "+ operador + " " + left);		
	}
	else if (nav == "nav6") { 
		if (top != '') {
			var i = eval("document.getElementById('"+layerName+"').style.top.indexOf(\"px\")");
			var inteiro = eval("parseInt(document.getElementById('"+layerName+"').style.top.substring(0,i+1))");
			if (operador == "-=") {
				eval("document.getElementById('"+layerName+"').style.top = "+inteiro+" - " +top);			
			}
			else if (operador == "+=") {
				eval("document.getElementById('"+layerName+"').style.top = "+inteiro+" + " +top);						
			}
			else {
				eval("document.getElementById('"+layerName+"').style.top "+ operador +" " + top);			
			}
		}
		if (left != '') {
			var i = eval("document.getElementById('"+layerName+"').style.left.indexOf(\"px\")");
			var inteiro = eval("parseInt(document.getElementById('"+layerName+"').style.left.substring(0,i+1))");
			if (operador == "-=") {
				eval("document.getElementById('"+layerName+"').style.left = "+inteiro+" - " +left);			
			}
			else if (operador == "+=") {
				eval("document.getElementById('"+layerName+"').style.left = "+inteiro+" + " +left);						
			}
			else {
				eval("document.getElementById('"+layerName+"').style.left "+ operador +" " + left);			
			}
		}
	}
} 
//------------------------------------------------------------------------
// Testa a posicao do layer tendo como base (left, right, top, bottom) e como operadores (<,>,==,!=,<=,>=)
function testaPosicaoLayer(layerName, base, posicao, operador, nav) {

	if(nav == "nav2" || nav == "nav3" || nav == "nav4") {
		return eval("document.layers."+layerName+"."+base+" "+operador+" " + posicao);
	}	
	else if(nav == "ie3" || nav == "ie4") { 
		if(base == "left") base = "pixelLeft";
		else if(base == "top") base = "pixelTop";
		else if(base == "right") base = "pixelRight";
		else if(base == "bottom") base = "pixelBottom";		
		return eval(layerName+".style."+base+" "+operador+" "+posicao);
	}
	else if(nav == "ie5" || nav == "ie6") { 
		if(base == "left") base = "pixelLeft";
		else if(base == "top") base = "pixelTop";
		else if(base == "right") base = "pixelRight";
		else if(base == "bottom") base = "pixelBottom";		
		return eval("document.getElementById('"+layerName+"').style."+base+" "+operador+" "+posicao);
	}
	else if (nav == "nav6") { 
		var i = eval("document.getElementById('"+layerName+"').style."+base+".indexOf(\"px\")");
		var inteiro = eval("parseInt(document.getElementById('"+layerName+"').style."+base+".substring(0,i+1))");
		return eval(inteiro+" "+operador+" "+posicao);	
	}	
}