var ImageBOX,ImageBOX= new Array();
function IMGpreload(){
	var N = IMGpreload.arguments[0];
	ImageBOX[N] = new Image();
	ImageBOX[N][0] = new Image();
	ImageBOX[N][1] = new Image();
	ImageBOX[N][1].src = IMGpreload.arguments[1];
}

function chanIMG() { 
	var M =  chanIMG.arguments[0];
	ImageBOX[M][0].src = document.images[M].src;
	document.images[M].src = ImageBOX[M][1].src; 
}
function restorIMG(){
	var R =  restorIMG.arguments[0];
	document.images[R].src = ImageBOX[R][0].src ; 
}

IMGpreload('navi01',"./images/goto_M_on.gif");
IMGpreload('navi02',"./images/goto_info_on.gif");
IMGpreload('navi03',"./images/goto_bio_on.gif");
IMGpreload('navi99',"./images/goto_contact_on.gif");