function insertURL (myField, i) {
    var defaultValue = 'http://';
	var URL = prompt('enter your url' ,defaultValue);
	
    if (URL) {
		ii = '[url='+ URL + ']';
		insertBB(ii,'click here[/url]');
	} else {
		insertBB('[url=]','[/url]');
	}
}
function insertBB(i,o) {
    if(o == undefined) { o=''; }
    var myField = document.getElementById('message');
	// IE selection support
	if (document.selection) {
		myField.focus();
	    sel = document.selection.createRange();
		if (sel.text.length > 0) {
			sel.text = i + sel.text + o;
		} else {
			sel.text = i + o;
		}
		myField.focus();
    // MOZILLA selection support
	} else if (myField.selectionStart || myField.selectionStart == '0') {
		var startPos = myField.selectionStart;
		var endPos = myField.selectionEnd;
		var cursorPos = endPos;
		var scrollTop = myField.scrollTop;
		if (startPos != endPos) {
			myField.value = myField.value.substring(0, startPos)
			+ i
            + myField.value.substring(startPos, endPos) 
            + o
            + myField.value.substring(endPos, myField.value.length);
			cursorPos = cursorPos + i.length + o.length;
		} else {
            myField.value = myField.value.substring(0, startPos) 
            + i 
            + o 
            + myField.value.substring(endPos, myField.value.length);
            cursorPos = startPos + i.length;
		}
		myField.focus();
		myField.selectionStart = cursorPos;
		myField.selectionEnd = cursorPos;
		myField.scrollTop = scrollTop;
	// SAFARI and others
	} else {
		myField.value += i+o;
		myField.focus();
	}
}