function OpenForm() {
  var filename   = arguments[0];
  var width      = arguments[1];
  var height     = arguments[2];
  var scroll		 = arguments[3] ? "yes" : "no";

	var top = (screen.height-height)/2;
	var left = (screen.width-width)/2;

	window.open(filename,
					"_blank",
					"top="+ top +","+
					"left="+ left +","+
					"width="+ width +","+
					"height="+ height +","+
					"location=no,"+
					"directories=no,"+
					"status=no,"+
					"menubar=no,"+
					"toolbar=no,"+
					"resizable=no,"+
					"scrollbars="+ scroll,
					true)
};

//delete selected row in table
function SelectRow(sender) {
	var form = sender.form;
	form.hiddenArray.value = "";
	
	var rows = form.elements["Row"];
	var state = sender.checked;
	var row = sender.parentNode.parentNode;
	
	if ( row.tagName.toLowerCase() != "tr" ) return false;
	
	if ( state ) {
		row.oldClass = row.className;
		row.className = "selected";
	}
	else
		row.className = row.oldClass;

	if (!rows.length) {
		form.hiddenArray.value = form.hiddenArray.value + rows.value + ",";
		return;
	}
	
	for(var i = 0; i <= rows.length - 1; i++) {
		if (rows[i].checked)
			form.hiddenArray.value = form.hiddenArray.value + rows[i].value + ",";
	}
};

function Confirm(sender) {
	var form = sender.form;
	var message = "Da li ste sigurni da zelite da obrisete knjige?";

	if(form.hiddenArray.value == "") {
		if(confirm(message)) {
			form.hiddenArray.value = "del";
			return;
		} else {
			form.hiddenArray.value = "";
		}
	}
	else {
		if(confirm(message)) {
		return;
		}
		else {
			form.hiddenArray.value = "";
		}
	}
};

// check text box 
function ChkField() {
	var objs = document.getElementsByTagName("INPUT"); 
	
	for (var i=0; i<objs.length; i++) {
		if (objs[i].type == "text") {
			if (objs[i].value == "") {
				alert("Niste popunili sva polja");
				return false;
			}
		}
	};
	return true;			
};

function WhichButton(sender) {
	var form = sender.form;
	
	if (sender.name == "btnDelete") {
		form.whichButton.value = 1;
	}
};

function ClearTextBox() {
	var objs = document.getElementsByTagName("INPUT"); 
	var objArea = document.getElementsByTagName("TEXTAREA");

	if (objArea.length) {
		objArea[0].value = "";
	}
	
	for (var i=0; i < objs.length; i++) {
		if (objs[i].type == "text") {
			objs[i].value = "";
		}
	}
};