fName = [
	"images/features_navisub_btn1on.gif",
	"images/features_navisub_btn2on.gif",
	"images/features_navisub_btn3on.gif",
	"images/features_navisub_btn4on.gif"
	];

prIMG = new Array();
for (i=0; i<fName.length; i++) {
	prIMG[i] = new Image();
	prIMG[i].src = fName[i];
}