function MM_findObjCalc(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObjCalc(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}
function calc(what)
{
	var T;
switch(what) {
	case 'mens':
		T = MM_findObjCalc( "mens_taux" ).value.replace(',','.')/100;
		if ((T<0.02) || (T>0.09))
			alert('Vous devez saisir un taux situé entre 2% et 9%');
		else {
			t = T/12;
			C = MM_findObjCalc( "mens_emprunt" ).value.replace(',','.');
			n = MM_findObjCalc( "mens_nbmens" ).value.replace(',','.');
			if (MM_findObjCalc( "mens_duree" )[1].checked) {
				n *= 12;
			}
			if( n == 0 ){
				alert("Vous devez saisir une durée d'emprunt");
			} else {
				MM_findObjCalc( "mens_mens" ).value = Math.round(100*C*(t/(1-(1/Math.pow(1+t,n)))))/100; }
			}
		break;
	case 'emprunt':
		T = MM_findObjCalc( "emprunt_taux" ).value.replace(',','.')/100;
		if ((T<0.02) || (T>0.09))
			alert('Vous devez saisir un taux situé entre 2% et 9%');
		else {
			t = T/12;
			n = MM_findObjCalc( "emprunt_nbmens" ).value.replace(',','.');
			if (MM_findObjCalc( "emprunt_duree" )[1].checked) {
				n *= 12;
			}
			m = MM_findObjCalc( "emprunt_mens" ).value.replace(',','.');
			MM_findObjCalc( "emprunt_emprunt" ).value = Math.round(m*((1-(1/Math.pow(1+t,n)))/t)); }
		break;
	case 'nbmens':
		T = MM_findObjCalc( "nbmens_taux" ).value.replace(',','.')/100;
		if ((T<0.02) || (T>0.09))
			alert('Vous devez saisir un taux situé entre 2% et 9%');
		else {
			t = T/12;
			C = MM_findObjCalc( "nbmens_emprunt" ).value.replace(',','.');
			m = MM_findObjCalc( "nbmens_mens" ).value.replace(',','.');
			MM_findObjCalc( "nbmens_nbmens" ).value = Math.round(Math.log(-1/(((C/m)*t)-1))/Math.log(1+t));
			//MM_findObjCalc( "nbmens_nbmens" ).value += ' mois (' + Math.round(MM_findObjCalc( "nbmens_nbmens" ).value/12) + ' an' + ((Math.round(MM_findObjCalc( "nbmens_nbmens" ).value/12)>1)?'s':'') + ')'; 
      }
		break;
	};
}