var browserName = navigator.appName;
var version = parseInt(navigator.appVersion)

var lock = "none"

if ( version  >= 3 )
{
		arrow0_on = new Image();
		arrow0_on.src = "Images/Arrow_on.gif";
		arrow0_off = new Image();
		arrow0_off.src = "Images/Arrow_off.gif";
		
		arrow1_on = new Image();
		arrow1_on.src = "Images/Arrow_on.gif";
		arrow1_off = new Image();
		arrow1_off.src = "Images/Arrow_off.gif";

		arrow2_on = new Image();
		arrow2_on.src = "Images/Arrow_on.gif";
		arrow2_off = new Image();
		arrow2_off.src = "Images/Arrow_off.gif";

		arrow3_on = new Image();
		arrow3_on.src = "Images/Arrow_on.gif";
		arrow3_off = new Image();
		arrow3_off.src = "Images/Arrow_off.gif";

		arrow4_on = new Image();
		arrow4_on.src = "Images/Arrow_on.gif";
		arrow4_off = new Image();
		arrow4_off.src = "Images/Arrow_off.gif";

		arrow5_on = new Image();
		arrow5_on.src = "Images/Arrow_on.gif";
		arrow5_off = new Image();
		arrow5_off.src = "Images/Arrow_off.gif";

		arrow6_on = new Image();
		arrow6_on.src = "Images/Arrow_on.gif";
		arrow6_off = new Image();
		arrow6_off.src = "Images/Arrow_off.gif";

		arrow7_on = new Image();
		arrow7_on.src = "Images/Arrow_on.gif";
		arrow7_off = new Image();
		arrow7_off.src = "Images/Arrow_off.gif";

		arrow8_on = new Image();
		arrow8_on.src = "Images/Arrow_on.gif";
		arrow8_off = new Image();
		arrow8_off.src = "Images/Arrow_off.gif";

		arrow9_on = new Image();
		arrow9_on.src = "Images/Arrow_on.gif";
		arrow9_off = new Image();
		arrow9_off.src = "Images/Arrow_off.gif";

		arrow10_on = new Image();
		arrow10_on.src = "Images/Arrow_on.gif";
		arrow10_off = new Image();
		arrow10_off.src = "Images/Arrow_off.gif";

		arrow11_on = new Image();
		arrow11_on.src = "Images/Arrow_on.gif";
		arrow11_off = new Image();
		arrow11_off.src = "Images/Arrow_off.gif";

		home_on = new Image();
		home_on.src = "Images/Home_on.gif";
		home_off = new Image();
		home_off.src= "Images/Home_off.gif";

		introduction_on = new Image();
		introduction_on.src = "Images/Introduction_on.gif";
		introduction_off = new Image();
		introduction_off.src = "Images/Introduction_off.gif";

		tutorial_on = new Image();
		tutorial_on.src = "Images/Tutorial_on.gif";
		tutorial_off = new Image();
		tutorial_off.src= "Images/Tutorial_off.gif";

		optimization_on = new Image();
		optimization_on.src = "Images/Optimization_on.gif";
		optimization_off = new Image();
		optimization_off.src= "Images/Optimization_off.gif";

		examples_on = new Image();
		examples_on.src = "Images/Examples_on.gif";
		examples_off=new Image();
		examples_off.src= "Images/Examples_off.gif";

		srcmain_on = new Image();
		srcmain_on.src = "Images/SrcMain_on.gif";
		srcmain_off = new Image();
		srcmain_off.src = "Images/SrcMain_off.gif";

		srcparser_on = new Image();
		srcparser_on.src = "Images/SrcParser_on.gif";
		srcparser_off = new Image();
		srcparser_off.src = "Images/SrcParser_off.gif";

		srctranslator_on = new Image();
		srctranslator_on.src = "Images/SrcTranslator_on.gif";
		srctranslator_off = new Image();
		srctranslator_off.src = "Images/SrcTranslator_off.gif";

		srcrollback_on = new Image();
		srcrollback_on.src = "Images/SrcRollback_on.gif";
		srcrollback_off = new Image();
		srcrollback_off.src = "Images/SrcRollback_off.gif";

		srcinterpreter_on = new Image();
		srcinterpreter_on.src = "Images/SrcInterpreter_on.gif";
		srcinterpreter_off = new Image();
		srcinterpreter_off.src = "Images/SrcInterpreter_off.gif";

		srcoptimizer1_on = new Image();
		srcoptimizer1_on.src = "Images/SrcOptimizer1_on.gif";
		srcoptimizer1_off = new Image();
		srcoptimizer1_off.src = "Images/SrcOptimizer1_off.gif";

		srcoptimizer2_on = new Image();
		srcoptimizer2_on.src = "Images/SrcOptimizer2_on.gif";
		srcoptimizer2_off = new Image();
		srcoptimizer2_off.src = "Images/SrcOptimizer2_off.gif";
}

function img_act(imgName)
{
	if (version  >= 3) 
	{
		imgOn=eval(imgName + "_on.src");
		document [imgName].src=imgOn;
	}
}

function img_inact(imgName)
{
	if (version  >= 3 ) 
		if (lock != imgName)
	{
		imgOff=eval(imgName + "_off.src");
		document [imgName].src=imgOff;
	}
}

function img_lock(imgName)
{
	lock = imgName	
}

function img_clear()
{
	if(version  >= 3)
		for(var count = 0; count <= 11; count++)
  			img_inact("arrow" + count);
	img_inact("home");
   img_inact("introduction");
	img_inact("tutorial");
	img_inact("optimization");
	img_inact("examples");
	img_inact("srcmain");
	img_inact("srcparser");
	img_inact("srctranslator");
	img_inact("srcrollback");
	img_inact("srcinterpreter");
	img_inact("srcoptimizer1");
	img_inact("srcoptimizer2");
}