/*
 ===============================================================================
 textareaResizer.js
 The script dynamically changes height of a textarea (actually any HTML element)
 (c) 2008 Leonid Shevtsov <leonid@shevtsov.me> (http://leonid.shevtsov.me)
 Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License
 ===============================================================================
*/

var minH = 50; // Minimal height of the field
var startH = 0;
var startY = 0;
var textarea = null;
var oldMouseMove = null;
var oldMouseUp = null;

function textareaResizer(e){
	if(e == null){
		e = window.event;
	}
	
	if(e.preventDefault){
		e.preventDefault();
	}

	resizer = (e.target != null) ? e.target : e.srcElement;
	textarea = document.getElementById(resizer.id.substr(0, resizer.id.length - 8));
	startY = e.clientY;
	startH = textarea.offsetHeight;
	oldMouseMove = document.onmousemove;
	oldMouseUp = document.onmouseup;

	document.onmousemove = textareaResizer_moveHandler;
	document.onmouseup = textareaResizer_cleanup;

	return false;
}

function textareaResizer_moveHandler(e){
	if(e == null){
		e = window.event;
	}
	
	if(e.button <= 1){
		curH = (startH + (e.clientY - startY));
		
		if(curH < minH)
			curH = minH;
		
		textarea.style.height = curH + 'px';
		
		return false;
	}
}

function textareaResizer_cleanup(e){
	document.onmousemove = oldMouseMove;
	document.onmouseup = oldMouseUp;
}