function einblenden(to_show) {

    var el_show = document.getElementById(to_show);
		el_show.style.display = 'block';
	
    var i, matches = new Array();
    var el2hide = document.getElementsByTagName('*');

    for(i = 0; i < el2hide.length; i++) {
    
        if(el2hide.item(i).className=='pic_hidden') {
            matches.push(el2hide.item(i));
        }
    }
   
    for ( i = 0; i < matches.length; i++ ) {
		
   		var el_hide = matches[i];
	
	    if ( el_hide != el_show ) {
		    el_hide.style.display = 'none';
	    }
	}
}