var buttPath = "images/but/en/";


var buttNorm = new Array (
	"about_us.jpg",
	"services.jpg",
	"instruments.jpg",
	"site_map.jpg",
	"contact_map.jpg",
	"quote_map.jpg",
	"contact.jpg",
	"quote.jpg"
);

var buttOver = new Array (
	"about_us_roll.jpg",
	"services_roll.jpg",
	"instruments_roll.jpg",
	"site_map_roll.jpg",
	"contact_roll_map.jpg",
	"quote_roll_map.jpg",
	"contact_roll.jpg",
	"quote_roll.jpg"
);
	
var buttNorm = preload_images ( buttPath, buttNorm );
var buttOver = preload_images ( buttPath, buttOver );

function preload_images ( img_path, img_array )
{
    var images = new Array;

    for ( var img_num=0; img_num<img_array.length; img_num++ ) {

        images[img_num] = new Image ();
        var url = img_path + img_array[img_num];
        images[img_num].src = url;
    }

    return ( images );
}

function buttonOver ( buttNum ) {
    if ( document.images ) {
        var objectID = document.images[ 'but' + buttNum ];
        objectID.src = eval( "buttOver[" + buttNum + "].src");
    }		
}

function buttonOut ( buttNum ) {
    if ( document.images ) {
        var objectID = document.images[ 'but' + buttNum ];
        objectID.src = eval( "buttNorm[" + buttNum + "].src");
    }
}