// confirm

function cnf (qstn, redir) {

    if (confirm(qstn)) document.location = redir;

}



// open window centered

function owc(url, winw, winh, params) {

    var date = new Date();

    var name = date.getTime();

    lf = Math.ceil((screen.width-winw)/2);

    tp = Math.ceil((screen.height-winh)/2);

    if (params.length > 0) params = ", " + params;

    var win = window.open(url, name, "width="+winw+", height="+winh+", top="+tp+", left="+lf+params);

}



// toggle visible

function tv(id) {

	var tab = document.getElementById(id);

	if (tab.style.display == "none") tab.style.display = "";

	else tab.style.display = "none";

}