var navdef_start, navdef_end, styleswitch, NS4, IE, NS6;

function bothBrowsers() {
    NS4 = false; IE4 = false; NS6 = false;
	
	if (document.getElementById) {
		NS6 = true;
		navdef_start="document.getElementById('";
		navdef_end="')";
		styleswitch=".style.";
		WWidth=window.innerWidth;
		WHeight=window.innerHeight;
	} else
	if (document.all) {
		IE4 = true;
		navdef_start="document.all.";
		navdef_end="";
		styleswitch=".style.";
		WWidth=document.body.clientWidth;
		WHeight=document.body.clientHeight;
	} else
	if (document.layers) {
		NS4 = true;
		navdef_start="document.layers.";
		navdef_end="";
		styleswitch=".";
		WWidth=window.innerWidth;
		WHeight=window.innerHeight;
	}
}

function layer_do(layer_name,layer_property,property_value,property_type) {
    if (layer_name=="main90" && NS4) layer_name = "main99.document.layers.main90";
	if (property_type=="str") eval(navdef_start+layer_name+navdef_end+styleswitch+layer_property+'="'+property_value+'"');
	 else
	if (property_type=="int") eval(navdef_start+layer_name+navdef_end+styleswitch+layer_property+'='+property_value);
}

function layer_pos(layer_name,layer_left,layer_top) {
	layer_do(layer_name,"left",layer_left,"int");
	layer_do(layer_name,"top",layer_top,"int");
}

function layer_p(layer_name,layer_property_ns,layer_property_ie,layer_property_g6) {
  if (NS6) {
	if (layer_property_g6) layer_property = layer_property_g6;
		else layer_property = layer_property_ie;
  } else if (IE4) {
	layer_property = layer_property_ie;
  } else if (NS4) {
    if (layer_name=="main90") layer_name = "main99.document.layers.main90";
    layer_property = layer_property_ns;
  }
  return(eval(navdef_start+layer_name+navdef_end+"."+layer_property));
}