สอบถามเรื่อง javascript autosum หน่อยครับติดไม่รู้จะแก้ยังไงครับ

function startCalc(){
  interval = setInterval("calc()",1);
}
function calc(){
  txt1 = document.perform.selft1.value;
  txt2 = document.perform.head1.value; 
  txt3 = document.perform.totalbuddy1.value;
  txt4 = document.perform.totalemp1.value; 
  //------------------------------>1.2
  txt9 = document.perform.selft2.value;
  txt10 = document.perform.head2.value; 
  txt11 = document.perform.totalbuddy2.value;
  txt12 = document.perform.totalemp2.value; 
  //------------------------------>1.3
  txt17 = document.perform.selft3.value;
  txt18 = document.perform.head3.value; 
  txt19 = document.perform.totalbuddy3.value;
  txt20 = document.perform.totalemp3.value; 
  //-------------------------->1.4
  txt21 = document.perform.selft4.value;
  txt22 = document.perform.head4.value; 
  txt23 = document.perform.totalbuddy4.value;
  txt24 = document.perform.totalemp4.value; 
  //---------------------------->1.5
  txt25 = document.perform.selft5.value;
  txt26 = document.perform.head5.value; 
  txt27 = document.perform.totalbuddy5.value;
  txt28 = document.perform.totalemp5.value; 
  //----------------------minuit
  txt111 = document.perform.lvget1.value;
  txt222 = document.perform.lvget2.value; 
  txt333= document.perform.lvget3.value;
  txt444 = document.perform.lvget4.value;
  txt555 = document.perform.lvget5.value;
  txt666 = document.perform.totalcompet1.value;
  txt777 = document.perform.totalcompet2.value; 
  txt888= document.perform.totalcompet3.value;
  txt999 = document.perform.totalcompet4.value;
  txt110 = document.perform.totalcompet5.value;
  txts1 = document.perform.totallv1.value;
  txts2 = document.perform.totallv2.value; 
  txts3 = document.perform.totallv3.value;
  txts4 = document.perform.totallv4.value;
  txts5 = document.perform.totallv5.value;
  txth1 = document.perform.addhybrid1.value;
  txth2 = document.perform.addhybrid2.value; 
  txth3 = document.perform.addhybrid3.value;
  txth4 = document.perform.addhybrid4.value;
  txth5 = document.perform.addhybrid5.value;
  txtd1 = document.perform.resscore1.value;
  txtd2 = document.perform.resscore2.value; 
  txtd3 = document.perform.resscore3.value;
  txtd4 = document.perform.resscore4.value;
  txtd5 = document.perform.resscore5.value;


  document.perform.totalcompet1.value = ((txt1 * 1) + (txt2 * 1) + (txt3 * 1)+ (txt4 * 1));
  document.perform.totalcompet2.value = ((txt9 * 1) + (txt10 * 1) + (txt11 * 1)+ (txt12 * 1));
  document.perform.totalcompet3.value = ((txt17 * 1) + (txt18 * 1) + (txt19 * 1) + (txt20 * 1));
  document.perform.totalcompet4.value = ((txt21 * 1) + (txt22 * 1) + (txt23 * 1) + (txt24 * 1));
  document.perform.totalcompet5.value = ((txt25 * 1) + (txt26 * 1) + (txt27 * 1) + (txt28 * 1));
  document.perform.differ1.value = ((txtd1 * 1) - (txt111 * 1));
  document.perform.differ2.value = ((txtd2 * 1) - (txt222 * 1));
  document.perform.differ3.value = ((txtd3 * 1) - (txt333 * 1));
  document.perform.differ4.value = ((txtd4 * 1) - (txt444 * 1));
  document.perform.differ5.value = ((txtd5 * 1) - (txt555 * 1));
  document.perform.totallv1.value = (((txt666 * 1)/100)*(5));
  document.perform.totallv2.value = (((txt777 * 1)/100)*(5));
  document.perform.totallv3.value = (((txt888 * 1)/100)*(5));
  document.perform.totallv4.value = (((txt999 * 1)/100)*(5));
  document.perform.totallv5.value = (((txt110 * 1)/100)*(5));
  document.perform.resscore1.value = ((txts1 * 1)+(txth1 * 1));
  document.perform.resscore2.value = ((txts2 * 1)+(txth2 * 1));
  document.perform.resscore3.value = ((txts3 * 1)+(txth3 * 1));
  document.perform.resscore4.value = ((txts4 * 1)+(txth4 * 1));
  document.perform.resscore5.value = ((txts5 * 1)+(txth5 * 1));
}
function stopCalc(){
  clearInterval(interval);
}