var isNN = (navigator.appName.indexOf("Netscape")!=-1);
			function autoTab(input,len, e) {
			var keyCode = (isNN) ? e.which : e.keyCode; 
			var filter = (isNN) ? [0,8,9] : [0,8,9,16,17,18,37,38,39,40,46];
			if(input.value.length >= len && !containsElement(filter,keyCode)) {
			input.value = input.value.slice(0, len);
			input.form[(getIndex(input)+1) % input.form.length].focus();
			}
			function containsElement(arr, ele) {
			var found = false, index = 0;
			while(!found && index < arr.length)
			if(arr[index] == ele)
			found = true;
			else
			index++;
			return found;
			}
			function getIndex(input) {
			var index = -1, i = 0, found = false;
			while (i < input.form.length && index == -1)
			if (input.form[i] == input)index = i;
			else i++;
			return index;
			}
			return true;
			}