var illLargeCurrent = null;

var illLargeNew = null;

var illSmallCurrent = null;

var illSmallNew = null;



function showIllustration(illId) 

{

    illLargeNew = document.getElementById('ill-large-' + illId);

    if(illLargeNew != illLargeCurrent) 

    {

        if(illLargeCurrent) 

        {

            illLargeCurrent.style.display = 'none';

        }

        if(illLargeNew) 

        {

            illLargeNew.style.display = 'block';

            illLargeCurrent = illLargeNew;

			repositionBlock('ill-large-' + illId);

        }

    }

    

}



function closeIllustration(illId) 

{

    illLargeCurrent = document.getElementById('ill-large-' + illId);

    illLargeCurrent.style.display = 'none';

    illLargeCurrent = null;

}



function repositionBlock(div_id)

{

    doc_width = document.documentElement.clientWidth;

    doc_height = document.documentElement.clientHeight;

    div_width = document.getElementById(div_id).offsetWidth;

    div_height = document.getElementById(div_id).offsetHeight;

    

    div_left = (doc_width - div_width) / 2;

    div_top = document.documentElement.scrollTop + (doc_height - div_height) / 2;



    if(div_top < 0)

        div_top = 0;

    if(div_left < 0)

        div_left = 0;



    document.getElementById(div_id).style.left = div_left + 'px';

    document.getElementById(div_id).style.top = div_top + 'px';

}