var vfields = {
	maxchars	 : 16,
	maxWidth	 : 300,
	initWidth	 : 150,
	charWidth	 : 5,
	vfield_class : 'vfield',
	init : function ()
	{
		var W3CDOM = (document.getElementsByTagName);
		if (!W3CDOM) return;
		var inputs = document.getElementsByTagName('input');
		for (var i=0; i<inputs.length; i++)
		{
			if (inputs[i].type == 'text' && inputs[i].className.indexOf(vfields.vfield_class) != -1)
			{
				inputs[i].onkeyup = vfields.checkLength;
			}
		}
	},
	checkLength : function ()
	{
		if (this.value.length >= vfields.maxchars)
		{
			var surplus	= this.value.length-vfields.maxchars;
			if ((vfields.initWidth + (surplus * vfields.charWidth)) < vfields.maxWidth)
			{
				this.style.width = (vfields.initWidth + (surplus * vfields.charWidth))+'px';
			}
		}
	}
}
window.onload = function ()
{
	vfields.init();
}