function nav_action(menu) {
    obj = document.getElementById(menu);
    nav_img = document.getElementById("nav_" + menu);
    if (obj.style.display!="none") {
      obj.style.display="none";
      nav_img.innerHTML="<img src='"+ imgPath + "ln_arrow_a.gif' border='0' class='lnArrowStyle' />";      
    }  
    else {
      obj.style.display="block";
      nav_img.innerHTML="<img src='" +imgPath+ "ln_arrow_b.gif' border='0' class='lnArrowStyle' />"; 
    }  
  }

function nav_action_lev1(menu) {
  obj = document.getElementById(menu);
  nav_img = document.getElementById("nav_" + menu);
  if (obj.style.display!="none") {
    obj.style.display="none";
    nav_img.innerHTML="<img src='" +imgPath+ "ln_arrow_a.gif' border='0' class='lnArrowStyle' />";      
}  
  else {
    obj.style.display="block";
    nav_img.innerHTML="<img src='" +imgPath+ "ln_arrow_b.gif' border='0' class='lnArrowStyle' />"; 
  }  
}

  function nav_action_lev2(menu) {
  obj = document.getElementById(menu);
  nav_img = document.getElementById("nav_" + menu);
  if (obj.style.display!="none") {
    obj.style.display="none";
    nav_img.innerHTML="<img src='" +imgPath+ "ln_arrow_lev2_a.gif' border='0' class='lnArrowStyle' />";      
}  
  else {
    obj.style.display="block";
    nav_img.innerHTML="<img src='" +imgPath+ "ln_arrow_lev2_b.gif' border='0' class='lnArrowStyle' />"; 
  }  
}

//initialize global layer-related variables and check browser type
	//var atHome = where=="98.0.0.0"?true:false;
    var extra_1 = ".";
    var extra_2 = ".";
	
	var nn = false; var ie = false; var ns6 = false; var nolayer = false;
	if (document.all) { 
	
		//browser is ie4+
		ie = true;
        extra_1 = ".all.";
        extra_2 = ".style.";
	
	} else if (document.layers) {
	  	
    // browser is NS4+ 
    nn = true;
	 
	} else if (document.getElementById) {
	 // browser NS6+ code (ie5+ also supports this syntax)
    ns6 = true;
        extra_1 = ".getElementById('";
        extra_2 = "').style.";
	} 
	else {
		// old non-layer browser
		nolayer = true;
	
	}
	
	if (nolayer) alert ("Your browser must be version 4.0 or higher (Internet Explorer or Netscape) to use the menus at the left to navigate Clarinex.com.");

function which_layer(showLayer) {
  for (i=0; i<leftNavLayers.length; i++){
      if (leftNavLayers[i] == showLayer) {
        eval("document" + extra_1 + leftNavLayers[i] + extra_2 + "visibility = 'visible'");
      }
      else {
        eval("document" + extra_1 + leftNavLayers[i] + extra_2 + "visibility = 'hidden'");
      }    
  }  
}


function topNavShowHide(which, vis) {
    eval("document" + extra_1 + which + extra_2 + "visibility = '" + vis + "'");
}

function doNothing() {}