var state = 'none';

function ShowHideBlock(elID) {
    if (state == 'block') { 
        state = 'none'; 
    } 
    else { 
        state = 'block';
    }
    
    if (document.all) { //IS IE 4 or 5 (or 6 beta)
        eval("document.all." + elID + ".style.display = state");
    }
    
    if (document.layers) { //IS NETSCAPE 4 or below
        document.layers[elID].display = state;
    }
    
    if (document.getElementById && !document.all) {
        tmp = document.getElementById(elID);
        tmp.style.display = state;
    }
}