/*----------------------------------------------------------------------------\
|                              Ratenrechner 0.6                               |
|-----------------------------------------------------------------------------|
|                          Created by Jens Kröger                             |
|                  			(http://www.pab5.de)                              |
|-----------------------------------------------------------------------------|
| Change																	  |
|-----------------------------------------------------------------------------|
| Created 2008-09-20 | All changes are in the log above. | Updated 2008-09-26 |
\----------------------------------------------------------------------------*/

function runde(x, n) {
  if (n < 1 || n > 14) return false;
  var e = Math.pow(10, n);
  var k = (Math.round(x * e) / e).toString();
  if (k.indexOf('.') == -1) k += '.';
  k += e.toString().substring(1);
  return k.substring(0, k.indexOf('.') + n+1);
}

function rechnen (){
	var b = parseFloat(document.getElementsByName('betrag')[0].value);
	var p = parseFloat(document.getElementsByName('prozent')[0].value);
	var m = parseFloat(document.getElementsByName('monate')[0].value);
	
	if(p == 0.0){p = 0.00001;}
	var q = 1.0+(p/100.0);
	var qn = Math.pow(q,1/12);
	var r = b*Math.pow(qn,m)/(Math.pow(qn,m)-1.0)*(qn - 1.0);
	document.getElementsByName('rate')[0].value = runde(r,2);

}