// setup test for Nav 4.0
var isIE = false;
var isNav = (navigator.appName.indexOf("Netscape")>=0);
var isNav4 = false;
var isIE4 = false;
var is5up = false;

if (isNav) {
	if (parseFloat(navigator.appVersion)<5) {
		isNav4 = true;
	} else {
		is5up = true;
	}
} else {
	isIE4=true;
	isIE=true;
	if (navigator.appVersion.indexOf("MSIE 5")>0) {
		isIE4 = false;
		is5up = true;
	}
}	

// Create a DHTML layer
function createLayer(name, left, top, width, height, visible, content) {
	  var layer;
	  if (isNav4) {
	    document.writeln('<layer name="' + name + '" left=' + left + ' top=' + top + ' width=' + width + ' height=' + height +  ' visibility=' + (visible ? '"show"' : '"hide"') +  '>');
	    document.writeln(content);
	    document.writeln('</layer>');
	    layer = getLayer(name);
	    layer.width = width;
	    layer.height = height;
	  } else {
	    document.writeln('<div id="' + name + '" style="position:absolute; overflow:none; left:' + left + 'px; top:' + top + 'px; width:' + width + 'px; height:' + height + 'px;' + ' visibility:' + (visible ? 'visible;' : 'hidden;') +  '">');
	    document.writeln(content);
	    document.writeln('</div>');
	  }
	  clipLayer(name, 0, 0, width, height);
}

// get the layer object called "name"
function getLayer(name) {
   if (isNav4)
      return(document.layers[name]);
   else if (isIE4) {
      if ( eval('document.all.' + name) != null) {
         layer = eval('document.all.' + name + '.style');
         return(layer);
      } else
         return(null);
   } else if (is5up) {
      var theObj = document.getElementById(name);
      return theObj.style
   } else
      return(null);
}

// move layer to x,y
function moveLayer(name, x, y) {		
  	var layer = getLayer(name);		
	if (layer != null) {
	  	if (isNav4)
	  	//if (document.layers)
    		layer.moveTo(x, y);
	 	else if (isIE) {
    		layer.left = x + "px";
   			layer.top  = y + "px";
		} else {
         layer.height = iHeight - y;
         layer.width	= iWidth - x;
         layer.left = x + "px";
         layer.top  = y + "px";
	  	}
	}
}

// set layer background color
function setLayerBackgroundColor(name, color) {		
  	var layer = getLayer(name);		
	if (layer != null) {
	   if (isNav4) 
    		layer.bgColor = color;
		else
    		layer.backgroundColor = color;
	}
}

// toggle layer to invisible
function hideLayer(name) {		
  	var layer = getLayer(name);		
	if (layer != null) {
	 	if (isNav4)
    		layer.visibility = "hide";
		else
         layer.visibility = "hidden";
	}
}

// toggle layer to visible
function showLayer(name) {		
  	var layer = getLayer(name);		
	if (layer != null) {
	  	if (isNav4)
    		layer.visibility = "show";
		else
         layer.visibility = "visible";
	}
}

// clip layer display to clipleft, cliptip, clipright, clipbottom
function clipLayer(name, clipleft, cliptop, clipright, clipbottom) {		
	var layer = getLayer(name);		
	if (layer != null) {
  		if (isNav4) {
         layer.clip.left   = clipleft;
         layer.clip.top    = cliptop;
         layer.clip.right  = clipright;
         layer.clip.bottom = clipbottom;
		} else if (isIE) {
			layer.clip = 'rect(' + cliptop + ' ' +  clipright + ' ' + clipbottom + ' ' + clipleft +')';
      } else {
     		layer.height = clipbottom - cliptop;
			layer.width	= clipright - clipleft;
			layer.top	= (cliptop+vspc) + "px";
			layer.left	= (clipleft+hspc) + "px";
		}
	}
}

// replace layer's content with new content
function replaceLayerContent(name, content) {
   if (isNav4) {
      var layer = getLayer(name);
      if (layer != null) {
         layer.document.open();
         layer.document.writeln(content);
         layer.document.close();
      }
   }  else if (isIE) {
      if (eval("document.all." + name) != null) {
         content = content.replace(/\'/g,"\\'");
         var str = "document.all." + name + ".innerHTML = '" + content + "'";
         eval(str);
      }
   }
}