/* Screen Width */
var w = new Number( screen.availWidth||screen.width );
/* Screen Height */
var h = new Number( screen.availHeight||screen.height );
var screenarea = new Number( ( w - 100 ) * ( h - 350 ) );
var cloudarea = new Number( 75 * 50 );
/* A solid 100% clouded background */
var cloudstofit = new Number( screenarea / cloudarea );
var clouds = new Number( Math.floor( cloudstofit / 20 ) );
var counter = new Number( 0 );

/* returns a number between 1 and the argument ) */
function randrange( number )
{
	var num = new Number();
	var range = new Number( 100 / number );
	num = Math.random() * 100;
	for( var i = 1; i < number; i++ )
		if( num < ( range * i ) )
			break;
	return i;
}

function drawcloud( identifier )
{
	var num = new Number( randrange( 12 ) );
	with( document )
	{
		write( '<div class = "cloud" id = "' + identifier + '">' );
		write( '<img src = "/images/cloud' + num + '.gif" />' );
		writeln( '</div>' );
	}
}

/* Randomly scatter clouds across the available screen */
function scatterclouds( numberofclouds )
{
	for( var i = 0; i < numberofclouds; i++ )
	{
		document.getElementById( 'cloud' + i ).style.left = randrange( ( w - 100 ) ) + "px";
		document.getElementById( 'cloud' + i ).style.top = randrange( ( h - 350 ) ) + "px";
		document.getElementById( 'cloud' + i ).style.display = 'block';
		document.getElementById( 'cloud' + i ).style.zIndex = 0;
	}
	//movingclouds = window.setInterval( 'moveclounds( ' + numberofclouds + ' )', 400 );
}

function moveclounds( numberofclouds )
{
	var cloudlayers = new Number( 4 );
	var left = new Number();
	for( var i = 0; i < numberofclouds; i++ )
	{
		if( ( counter * ( numberofclouds / cloudlayers ) ) < i )
		{
			left = document.getElementById( 'cloud' + i ).style.left;
			left = left.substring( 0, left.length - 2 );
			if( left > w ) left = -80;
			else left++;
			document.getElementById( 'cloud' + i ).style.left = left + "px";
		}
	}
	counter++;
	if( counter > cloudlayers ) counter = 0;
}