function getCaptcha( imgobj )
{
	if ( imgobj.src.indexOf( 'code' ) >= 0 )
		return;
	var rnd = '';
	var chars = '1234567890'; //'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
	for ( idx = 0; idx < 4; idx++ ) 
		rnd += chars.charAt( Math.round( Math.random() * chars.length ) );
	imgobj.src = imgobj.src + '?code=' + rnd;
	document.getElementById( 'code' ).value = rnd;
}