var CSS_OTF;

function createCss(){
	try{
		CSS_OTF = document.createStyleSheet();
	}catch(e){
		var css = document.createElement("style");
		document.getElementsByTagName("head")[0].appendChild(css);
		CSS_OTF = document.styleSheets[document.styleSheets.length -1]
	}
}
createCss();

var mmedia_sel = new Array();
var mmedia={};

function ponImagenes(){
    var tam = mmedia_sel.length
        for(i=0; i<tam; i++) {
            mm=document.getElementById(mmedia_sel[i])
                if (mm) {
                    modShow(mmedia_sel[i]);
                }
        }
}

function prevModule(node){
    while(node.id.indexOf("ale_")==-1){
        node = node.parentNode
    }
    node.style.display="none";

    var sibling=node;
    do {
        sibling = sibling.previousSibling;
        if (!sibling) sibling=node.parentNode.lastChild;
    } while (sibling.nodeType!=1)

    sibling.style.display="block";
    modShow(sibling.id);
    return false;
}

function nextModule(node){
    while(node.id.indexOf("ale_")==-1){
        node = node.parentNode;
    }
    node.style.display="none";

    var sibling=node;
    do {
        sibling = sibling.nextSibling;
        if (!sibling) sibling=node.parentNode.firstChild;
    } while (sibling.nodeType!=1)

    sibling.style.display="block";
    modShow(sibling.id);
    return false;
}
function modShow(mod_id){
    var mmdata = mmedia[mod_id];
    if (mmdata){
        if (mmdata.type == 'img')
            var node = document.getElementById(mod_id+'_img');
        else
            var node = document.getElementById('iframe_content_'+mod_id);
        node.src = mmdata.src;
    }
}

function randomDiv(id, tam, orden) {
    var aleatorio = ((orden == 'A') ? Math.floor(Math.random() * tam) : 0);
    for(var i=0; i<tam; i++) {
        var cid = id+"ale_"+i
            var imid = cid+"_img"
            if (aleatorio==i) {
                if (orden == 'A'){
                    var mmdata = mmedia[cid];
                    if (mmdata){
                        mmedia_sel.push(cid);
                        if (mmdata.type == 'img')
                            setBgImage(imid, mmdata.src);
                    }
                }
            }
            else {
                setDisplay(cid,"none");
            }
    }
}
function setDisplay(name,display){
    try{
        CSS_OTF.addRule("#"+name,"display:"+display+";")
    }catch(e){
        CSS_OTF.insertRule("#"+name+" { display: "+display+" }", 0)
    }
}

function setBgImage(name, url) {
    try{
        CSS_OTF.addRule("#"+name,"background-image:url('"+url+"');");
    }catch(e){
        CSS_OTF.insertRule("#"+name+" { background-image:url('"+url+"') }", 1);
    }
}