var COLLAPSIBLE_PARENT_NAME = "collapsible"; 
var COLLAPSIBLE_PARENT_TYPE = "div"; 
var COLLAPSIBLE_CHILD_TYPE = "p"; 
var COLLAPSIBLE_CHILD_TYPE = "ul";
var COLLAPSIBLE_CHILD_TYPE = "table"; 

var COLLAPSIBLE_EXPAND = "[seguir leyendo]"; 
var COLLAPSIBLE_SHRINK = "[cerrar]"; 

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

assignCollapse = function (div) { 
    var button = document.createElement('a'); 
    button.style.cursor='pointer'; 
    button.setAttribute('leer', COLLAPSIBLE_EXPAND); 
    button.setAttribute('cerrar', COLLAPSIBLE_SHRINK); 
    button.setAttribute('state', -1); 
    button.innerHTML='dsds'; 
    div.insertBefore(button, div.getElementsByTagName(COLLAPSIBLE_CHILD_TYPE)[0]); 

    button.onclick=function(){ 
        var state = -(1*this.getAttribute('state')); 
        this.setAttribute('state', state); 
        this.parentNode.getElementsByTagName(COLLAPSIBLE_CHILD_TYPE)[0].style.display=state==1?'none':'block'; 
        this.innerHTML = this.getAttribute(state==1?'leer':'cerrar'); 
    };                    
    button.onclick(); 
} 


window.onload=init;