var i  = new Array(4);
var x=0;
for (x=0; x<4; x++)
{
i[x]=new Image();
}

i[0].src="images/leftarrow.jpg";
i[1].src="images/leftarrow-lit.jpg";
i[2].src="images/rightarrow.jpg";
i[3].src="images/rightarrow-lit.jpg";