function change_background ( obj , state ) {
	if ( state == "on" ) {
		if ( obj.id == "contentcenter_leftbutton" ) {
			var limg = document.getElementById("contentcenter_leftbutton_limg");
			var cimg = document.getElementById("contentcenter_leftbutton_cimg");
			var rimg = document.getElementById("contentcenter_leftbutton_rimg");
			limg.style.backgroundImage = 'url(../images/switch_content_leftside_blue_taller.gif)';
			cimg.style.backgroundImage = 'url(../images/switch_content_bg_blue_taller.gif)';
			rimg.style.backgroundImage = 'url(../images/switch_content_middleleft_blue_taller.gif)';
		} else if ( obj.id == "contentcenter_rightbutton" ) {
			var limg = document.getElementById("contentcenter_rightbutton_limg");
			var cimg = document.getElementById("contentcenter_rightbutton_cimg");
			var rimg = document.getElementById("contentcenter_rightbutton_rimg");
			limg.style.backgroundImage = 'url(../images/switch_content_middleright_blue_taller.gif)';
			cimg.style.backgroundImage = 'url(../images/switch_content_bg_blue_taller.gif)';
			rimg.style.backgroundImage = 'url(../images/switch_content_rightside_blue_taller.gif)';
		}
	} else if ( state == "off" ) {
		if ( obj.id == "contentcenter_leftbutton" ) {
			var limg = document.getElementById("contentcenter_leftbutton_limg");
			var cimg = document.getElementById("contentcenter_leftbutton_cimg");
			var rimg = document.getElementById("contentcenter_leftbutton_rimg");
			limg.style.backgroundImage = 'url(../images/switch_content_leftside_taller.gif)';
			cimg.style.backgroundImage = 'url(../images/switch_content_bg_taller.gif)';
			rimg.style.backgroundImage = 'url(../images/switch_content_middleleft_taller.gif)';
		} else if ( obj.id == "contentcenter_rightbutton" ) {
			var limg = document.getElementById("contentcenter_rightbutton_limg");
			var cimg = document.getElementById("contentcenter_rightbutton_cimg");
			var rimg = document.getElementById("contentcenter_rightbutton_rimg");
			limg.style.backgroundImage = 'url(../images/switch_content_middleright_taller.gif)';
			cimg.style.backgroundImage = 'url(../images/switch_content_bg_taller.gif)';
			rimg.style.backgroundImage = 'url(../images/switch_content_rightside_taller.gif)';
		}
	}
}