// Left Panel (image links)
img_zone1_off = new Image();
img_zone1_on = new Image();
img_zone1_off.src = "/images/exercises/zone1_off.jpg";
img_zone1_on.src = "/images/exercises/zone1_on.jpg";

img_zone2_off = new Image();
img_zone2_on = new Image();
img_zone2_off.src = "/images/exercises/zone2_off.jpg";
img_zone2_on.src = "/images/exercises/zone2_on.jpg";

img_zone3_off = new Image();
img_zone3_on = new Image();
img_zone3_off.src = "/images/exercises/zone3_off.jpg";
img_zone3_on.src = "/images/exercises/zone3_on.jpg";

// Upper right corner of page (text links)
img_zone1_text_off = new Image();
img_zone1_text_on = new Image();
img_zone1_text_off.src = "/images/text/exercises/upper_off.gif";
img_zone1_text_on.src = "/images/text/exercises/upper_on.gif";

img_zone2_text_off = new Image();
img_zone2_text_on = new Image();
img_zone2_text_off.src = "/images/text/exercises/lower_off.gif";
img_zone2_text_on.src = "/images/text/exercises/lower_on.gif";

img_zone3_text_off = new Image();
img_zone3_text_on = new Image();
img_zone3_text_off.src = "/images/text/exercises/obliques_off.gif";
img_zone3_text_on.src = "/images/text/exercises/obliques_on.gif";

function imgTurnOn( imgName )
{
	document[imgName].src = eval( imgName + "_on.src" );
}

function imgTurnOff( imgName )
{
	document[imgName].src = eval( imgName + "_off.src" );
}

function Press( zone )
{
	imgTurnOn( "img_zone" + zone );
	imgTurnOn( "img_zone" + zone + "_text" );
}

function Release( zone )
{
	imgTurnOff( "img_zone" + zone );
	imgTurnOff( "img_zone" + zone + "_text" );
}