variables numéricas en javascript

[monoswim]

Código:

      var total = 0;
      total = eval(document.formulario.form1.value);
      total += eval(document.formulario.form2.value);
      total += eval(document.formulario.form3.value);
//	  total += parseFloat(document.formulario.form4.value);
//	  total += parseFloat(document.formulario.form5.value);
//	  total += parseFloat(document.formulario.form6.value);
//	  total += parseFloat(document.formulario.form7.value);
//	  total += parseFloat(document.formulario.form8.value);
//	  total += parseFloat(document.formulario.form9.value);
//	  total += parseFloat(document.formulario.form10.value);
//	  total += parseFloat(document.formulario.form11.value);
//	  total += parseFloat(document.formulario.form12.value);
//	  total += parseFloat(document.formulario.form13.value);
//	  total += parseFloat(document.formulario.form14.value);
//	  total += parseFloat(document.formulario.form15.value);
//	  total += parseFloat(document.formulario.form16.value);
//	  total += parseFloat(document.formulario.form17.value);
//	  total += parseFloat(document.formulario.form18.value);
//	  total += parseFloat(document.formulario.form19.value);
//	  total += parseFloat(document.formulario.form20.value);
//var total = sumar(form_array);
//var total = document.formulario.form1.value+document.formulario.form2.value+document.formulario.form3.value+document.formulario.form4.value+document.formulario.form5.value+document.formulario.form6.value+document.formulario.form7.value+document.formulario.form8.value+document.formulario.form9.value+document.formulario.form10.value+document.formulario.form11.value+document.formulario.form12.value+document.formulario.form13.value+document.formulario.form14.value+document.formulario.form15.value+document.formulario.form16.value+document.formulario.form17.value+document.formulario.form18.value+document.formulario.form19.value+document.formulario.form20.value;
//document.formulario.form_prom.value = total;
alert(total);