// Funktion um Mengen im Warenkob auf der Rechnung noch zu ändern

function chg_amount(action,id){
	var the_value = parseInt(eval("document.change_"+id+".amount.value"));
	if(action == "add"){
		the_value += 1;
		eval("document.change_"+id+".amount.value = the_value");
	}
	if(action == "dec"){
	the_value -= 1;
		if (the_value <= 1){
			the_value = 1;
		}
	eval("document.change_"+id+".amount.value = the_value");
	}
}

// Popupwindow

function detail_window(theURL,winName,features){
	fenster= open(theURL,winName,features);
}

// Limitiert die Maximal mögliche Anzahl von Zeichen

function check_length(the_field, max_length){
	var now_text	= document.getElementById(the_field).value;
	var now_chars 	= now_text.length;
	if (now_chars >= max_length){
		document.getElementById(the_field).value = now_text.substr(0,max_length-1);
		alert ("Bitte maximal " + max_length + " Zeichen benutzen!");		
	}	
}


function toggle_lad(id){
	var lad = document.getElementById(id)
	
	if (lad.style.visibility == "hidden"){
		lad.style.visibility = "visible";
	}else{
	lad.style.visibility = "hidden";
	}
}