var idx = 9;
var extents = new Array(.0003, .003, .008, .017, .033, .083, .17, .25, .5, 1);

function calcScalebarPos()
{
	idx = 9;

	var i = 0;

	var ydiff = parseFloat(slider_maxy - slider_miny);
	var currdiff = parseFloat(maxy - miny).toFixed(4);

	for (i = 0; i < extents.length; i++) {
		
		if (i < (extents.length - 1)) {
			var l = parseFloat(ydiff * extents[i]).toFixed(3);
			var h = parseFloat(ydiff * extents[(i + 1)]).toFixed(3);

			
			if (l <= currdiff && currdiff < h ) {
				idx = i;
				break;
			}
		}
	}

	colorize();
}

function jumpUp() {
	if (okToSend) {
	        if (idx < (extents.length - 1)) {
        	        idx++;
			recalcXY();
        	}
	}

}

function jumpDown() {
	if (okToSend) {
	        if (idx > 0) {
        	        idx--;
			recalcXY();
        	}
	}
}


function colorize() {
        var i =0;
        
        for (i = 0; i < (idx + 1); i++) {
                var m = document.getElementById('sb_' + i);
                m.src = 'images/scalebar/9.gif';
        }

        for (i = idx; i < extents.length; i++) {
                var m = document.getElementById('sb_' + i);
                m.src = 'images/scalebar/9_on.gif';
        }
}

function recalcXY() {

	var center_x = minx - ((minx - maxx)/2);
	var center_y = ((maxy - miny) / 2) + miny;

	var offset = ((slider_maxy - slider_miny) / 2) * extents[idx];

	maxx = center_x + offset;
	minx = center_x - offset;
	maxy = center_y + offset;
	miny = center_y - offset;

	getMapWithCurrentExtent();

}

function jumpTo(i) {
	if (okToSend) {
        	idx = i;
		recalcXY();
	}
}