function sig_show()
{
	var l_nIdx = parseInt(document.getElementById('img').value);
	if (l_nIdx < 1)
		l_nIdx = 1;
	if (l_nIdx > parseInt(document.getElementById('numback').value))
		l_nIdx = parseInt(document.getElementById('numback').value);
	// Wet setzen:
	document.getElementById('img').value = l_nIdx;
	if (l_nIdx < 10)
		l_nIdx = '0' + l_nIdx;
	document.getElementById('background').src = document.getElementById('rawpath').value + '/background_' + l_nIdx + '.jpg';
}

function sig_first()
{
	document.getElementById('img').value = "1";
	sig_show();
}
function sig_prev()
{
	document.getElementById('img').value = parseInt(document.getElementById('img').value) - 1;
	sig_show();
}
function sig_next()
{
	document.getElementById('img').value = parseInt(document.getElementById('img').value) + 1;
	sig_show();
}
function sig_last()
{
	document.getElementById('img').value = parseInt(document.getElementById('numback').value);
	sig_show();
}