var DHTML = (document.getElementById || document.all || document.layers);
 
function getObj(name) {
    if (document.getElementById) {
        this.obj = document.getElementById(name);
        this.style = document.getElementById(name).style;
    }
    else if (document.all) {
        this.obj = document.all[name];
        this.style = document.all[name].style;
    }
    else if (document.layers) {
        this.obj = document.layers[name];
        this.style = document.layers[name];
    }
}
 
function checkBoxes(obj_input, form)
{
	bol_is_checked = (obj_input.checked)?true:false
    for (x=0;x<form.length;x++)
		form.elements[x].checked = bol_is_checked;
}
 
function pokaz(co) {
    if (!DHTML) return;
    var x = new getObj(co);
    var akt = x.style.display;
    if (akt == 'block') {
        x.style.display = 'none';
    } else {
        x.style.display = 'block';
    }
}