function click_right () {

    document.getElementById("box_left").style.border="none";
    document.getElementById("box_left").style.borderBottom="10px solid #cccccc";
    document.getElementById("box_inner_left").style.border = "10px solid #f0f0f0";
    document.getElementById("box_left").style.width="381px";

    document.getElementById("box_right").style.border="10px solid #cccccc";
    document.getElementById("box_right").style.borderBottom="none";
    document.getElementById("box_inner_right").style.border = "none";
    document.getElementById("box_right").style.width="361px";

    document.getElementById("box_right").style.cursor="default";
    document.getElementById("box_left").style.cursor="pointer";

    document.getElementById("content_left").style.display = "none";
    document.getElementById("content_right").style.display = "block";

	document.getElementById('link_previous').style.display='block';
	document.getElementById('link_next').style.display='none';

}

function click_left () {

    document.getElementById("box_right").style.border="none";
    document.getElementById("box_right").style.borderBottom="10px solid #cccccc";
    document.getElementById("box_inner_right").style.border = "10px solid #f0f0f0";
    document.getElementById("box_right").style.width="381px";

    document.getElementById("box_left").style.border="10px solid #cccccc";
    document.getElementById("box_left").style.borderBottom="none";
    document.getElementById("box_inner_left").style.border = "none";
    document.getElementById("box_left").style.width="361px";

    document.getElementById("box_left").style.cursor="default";
    document.getElementById("box_right").style.cursor="pointer";

    document.getElementById("content_right").style.display = "none";
    document.getElementById("content_left").style.display = "block";

	document.getElementById('link_next').style.display='block';
	document.getElementById('link_previous').style.display='none';

}