function insertAtCursor(myField, myValue) {
	myField.focus();
	if (document.selection) {
		myField.focus();
		sel = document.selection.createRange();
		sel.text = myValue;
	}
	else if (myField.selectionStart || myField.selectionStart == '0') {
		var startPos = myField.selectionStart;
		var endPos = myField.selectionEnd;
		myField.value = myField.value.substring(0, startPos) + myValue + myField.value.substring(endPos, myField.value.length);
	}
	else {
			myField.value += myValue;
	}
}

var j = 0;
var k = 0;
var l = 0;
	
function insertBold(form) {
	if (j % 2 == 0) {
		insertAtCursor(form, '[b]');
	} else {
		insertAtCursor(form, '[/b]');
	}
	j += 1;
}
function insertUnderline(form) {
	if (k % 2 == 0) {
		insertAtCursor(form, '[u]');
	} else {
		insertAtCursor(form, '[/u]');
	}
	k += 1;
}
function insertItalic(form) {
	if (l % 2 == 0) {
		insertAtCursor(form, '[i]');
	} else {
		insertAtCursor(form, '[/i]');
	}
	l += 1;
}
function insertUrl(form) {
	insertAtCursor(form, '[url]http://[/url]');
}
function insertImg(form) {
	insertAtCursor(form, '[img]http://[/img]');
}