var COLLAPSABLE_PARENT_NAME = "collapsable"; 
var COLLAPSABLE_PARENT_TYPE = "div"; 
var COLLAPSABLE_CHILD_TYPE = "div";
var COLLAPSABLE_BUTTON_TYPE = "p";

function init() { 
    if(document.getElementById && document.createTextNode) { 
        var entries = document.getElementsByTagName(COLLAPSABLE_PARENT_TYPE); 
        for(i=0;i<entries.length;i++) 
            if (entries[i].className==COLLAPSABLE_PARENT_NAME) 
                assignCollapse(entries[i]); 
    } 
} 

function assignCollapse(div) { 
    var button = div.getElementsByTagName(COLLAPSABLE_BUTTON_TYPE)[0];
    var content = button.parentNode.getElementsByTagName(COLLAPSABLE_CHILD_TYPE)[0];
    button.style.cursor='pointer';
    
    if(content.className == 'open') {
        content.setAttribute('state', 1);
    } else {
        content.setAttribute('state', -1);
    }
    
    button.onclick = function(){ 
        var old_state = content.getAttribute('state');
        var state = -(1*old_state);
        content.setAttribute('state', state);
        content.style.display=state==1?'none':'block';
    };                    
    button.onclick();
}