var W3C = document.getElementById? true : false;
var NN4 = document.layers? true : false;
var IE4 = document.all? true : false;


function move_in(img_name,img_src) 
{
	document[img_name].src=img_src;
}
function move_out(img_name,img_src)
{
		document[img_name].src=img_src;
}

function putStr(string)
{
	document.insertform.message.value += string;
}

function show(layerName)
{
	if (W3C)
	{
		document.getElementById(layerName).style.visibility = "visible";
	}
	else if (IE4) 
	{
		document.all[layerName].style.visibility = "visible";
	}
	else if(NN4) 
	{
		document.layers[layerName].visibility = "show";
	}
}




function hide(layerName)
{
	if (W3C)
	{
		document.getElementById(layerName).style.visibility = "hidden";
	}
	else if (IE4) 
	{
		document.all[layerName].style.visibility = "hidden";
	}
	else if(NN4)
	{
		document.layers[layerName].visibility = "hidden";
	}
}

function swapVisibility(layerName,layer2,distance)
{
	if (W3C)
	{
		if (document.getElementById(layerName).style.visibility == "visible")
		{
			hide(layerName);
			moveBack(layer2,distance);
		}
		else
		{
			show(layerName);
			moveForth(layer2);
		};
	}
	else if (IE4) 
	{
		document.all[layerName].style.visibility = "visible";
	}
	else if(NN4) 
	{
		document.layers[layerName].visibility = "show";
	}
}

function move(layer1,layer2,distance)
{
	document.getElementByID(layer1).style.top = (parseInt(document.getElementByID(layer2).style.top) + distance) + "px";
}

function moveForth(layerName)
{
	if (W3C)
	{
		document.getElementById(layerName).style.top = "0px";
	}
	else if (IE4) 
	{
		document.all[layerName].style.top = "0px";
	}
	else if(NN4) 
	{
		document.layers[layerName].top = "0px";
	}
}
function moveBack(layerName,distance)
{
	if (W3C)
	{
		document.getElementById(layerName).style.top =distance;
	}
	else if (IE4) 
	{
		document.all[layerName].style.top = distance;
	}
	else if(NN4) 
	{
		document.layers[layerName].top = distance;
	}
}

function goToURL(question,url)
{
 var where_to= confirm(question);
 if (where_to== true)
 {
   window.location=url;
 }
}