// HTML and javascript by Marco Balestra <balestra@cesmail.net>

function parSshowGetCurrent(s) {
	var x = getObj(s+'CtrlCurrent');
	return (x) ? parseInt(x.innerHTML) : 1;
}

function parSshowGetTotal(s) {
	var x = getObj(s+'CtrlTotal');
	return (x) ? parseInt(x.innerHTML) : 1;
}

function parSshowFirst(s) { parSshowJump(s,1) }

function parSshowPrev(s) { parSshowJump(s, parSshowGetCurrent(s) -1) }

function parSshowNext(s) { parSshowJump(s, parSshowGetCurrent(s) +1) }

function parSshowLast(s) { parSshowJump(s, parSshowGetTotal(s)) }

function parSshowJump(s,dest) {
	var c = parSshowGetCurrent(s);
	var t = parSshowGetTotal(s);
	dest = parseInt(dest);
	if ((dest == c ) || (dest < 1) || (dest > t)) return void(0);
	var cdiv = getObj(s+'_'+c);
	var destdiv = getObj(s+'_'+dest);
	if ( (! (cdiv)) || (! (destdiv)) ) return void(0);
	cdiv.style.display = 'none';
	destdiv.style.display = 'block';
	var x = getObj(s+'CtrlCurrent');
	if (x) x.innerHTML = dest.toString();
	getObj(s+'CtrlPrevFirst').disabled = (dest <= 1);
	getObj(s+'CtrlPrevPrev').disabled = (dest <= 1);
	getObj(s+'CtrlNextLast').disabled = (dest >= t);
	getObj(s+'CtrlNextNext').disabled = (dest >= t);
}

function parSshowJumpTo(s) {
	var q;
	switch (params.lang) {
		case 'it': q = 'Vai alla slide numero:'; break;
		default  : q = 'Jump to slide number:';
	}
	var ris = window.prompt(q);
	parSshowJump(s,ris.toString().replace(/[^0-9]/g,''));
}