function Calculate() 
{


// Set the unit conversion factors:

 k1 = (2*3.1416/1)/(60/1)*(1/1000)/(1/3600);
 k2 =(1/1000)/(1/3600);
 k3 =1000*1000/(733.333333333333*3600*3600);
 
 
// Read the input data form the forms:

 Mass = document.form1.Mass.value;
 Power = document.form1.Power.value;
 Rpm = document.form1.Rpm.value;
 Tyre_D = document.form1.Tyre_D.value;
 
 i1 = document.form1.i1.value;
 i2 = document.form1.i2.value;
 i3 = document.form1.i3.value;
 i4 = document.form1.i4.value;
 i5 = document.form1.i5.value;
 i6 = document.form1.i6.value;
 i7 = document.form1.i7.value;
 
 
// crescent order: if there is any "right" value smaller than it's "left" make it equal to the "left":
// the following must be before calculations, because it also avoids DIVISIONs BY ZERO:
 
 if (i2 < i1) { i2 = i1;}
 if (i3 < i2) { i3 = i2;}
 if (i4 < i3) { i4 = i3;}
 if (i5 < i4) { i5 = i4;}
 if (i6 < i5) { i6 = i5;}
 if (i7 < i6) { i7 = i6;}

 
// Calculate the maximum speed after each gear:

 Vmax1 = Rpm*i1*Tyre_D/2*k1;
 Vmax2 = Rpm*i2*Tyre_D/2*k1;
 Vmax3 = Rpm*i3*Tyre_D/2*k1;
 Vmax4 = Rpm*i4*Tyre_D/2*k1;
 Vmax5 = Rpm*i5*Tyre_D/2*k1;
 Vmax6 = Rpm*i6*Tyre_D/2*k1;
 Vmax7 = Rpm*i7*Tyre_D/2*k1;
 
 
// When 100km/ are attained, which is gear at that moment?
 
 i_100 = 0;
 if (Vmax1 > 100 && i_100 == 0) { i_100 = 1;}
 if (Vmax2 > 100 && i_100 == 0) { i_100 = 2;}
 if (Vmax3 > 100 && i_100 == 0) { i_100 = 3;}
 if (Vmax4 > 100 && i_100 == 0) { i_100 = 4;}
 if (Vmax5 > 100 && i_100 == 0) { i_100 = 5;}
 if (Vmax6 > 100 && i_100 == 0) { i_100 = 6;}
 if (Vmax7 > 100 && i_100 == 0) { i_100 = 7;}
 
 
// Thus, if i_100 is STILL_ZERO, then this means that the gears are too short to attain 100km/h
 
 if (i_100 == 0) {javascript:alert('Greater ratios are required.');}
 
 if (i_100 != 0) {
 
 
// Calculate the acceleretion values corresponding to each ratio:
     
      a1 = 733.333333333333*Power/(Vmax1*Mass)*k2;
      a2 = 733.333333333333*Power/(Vmax2*Mass)*k2;
      a3 = 733.333333333333*Power/(Vmax3*Mass)*k2;
      a4 = 733.333333333333*Power/(Vmax4*Mass)*k2;
      a5 = 733.333333333333*Power/(Vmax5*Mass)*k2;
      a6 = 733.333333333333*Power/(Vmax6*Mass)*k2;
      a7 = 733.333333333333*Power/(Vmax7*Mass)*k2;
     
      
// Calculate the time spent on each reatio:
      
      t1 = (Vmax1-0)/(a1*k2);
      t2 = (Vmax2-Vmax1)/(a2*k2);
      t3 = (Vmax3-Vmax2)/(a3*k2);
      t4 = (Vmax4-Vmax3)/(a4*k2);
      t5 = (Vmax5-Vmax4)/(a5*k2);
      t6 = (Vmax6-Vmax5)/(a6*k2);
      t7 = (Vmax7-Vmax6)/(a7*k2);
      
     
// We already know which will be the last gear. Now we must calculate the shorter time spent on that gear:
     
      if (i_100 == 1) {MT_Time = (100-0)/(a1*k2);}
      if (i_100 == 2) {MT_Time = t1 + (100-Vmax1)/(a2*k2);}
      if (i_100 == 3) {MT_Time = t1 + t2 + (100-Vmax2)/(a3*k2);}
      if (i_100 == 4) {MT_Time = t1 + t2 + t3 + (100-Vmax3)/(a4*k2);}
      if (i_100 == 5) {MT_Time = t1 + t2 + t3 + t4 + (100-Vmax4)/(a5*k2);}
      if (i_100 == 6) {MT_Time = t1 + t2 + t3 + t4 + t5 + (100-Vmax5)/(a6*k2);}
      if (i_100 == 7) {MT_Time = t1 + t2 + t3 + t4 + t5 + t6 + (100-Vmax6)/(a7*k2);}


// Finnaly, we must calculate the CVT_Time, and percentages, which is easier:
     
     CVT_Time = 100*100/2*Mass/Power*k3;
     perc_of_MT = CVT_Time/MT_Time*100;
     CVT_more_perf = MT_Time/CVT_Time*100-100;
     
    
// Output the ratios values that were, in fact, used:
     
     document.form1.i1.value = i1;
     document.form1.i2.value = i2;
     document.form1.i3.value = i3; 
     document.form1.i4.value = i4;
     document.form1.i5.value = i5;
     document.form1.i6.value = i6;
     document.form1.i7.value = i7;
     
     
// Unexisting ratios are reset to ZERO: 
// Remember that this program has previously replaced tha last null ratios by the reates non-Zero.

     if (i7 == i6) {document.form1.i7.value = 0;}
     if (i6 == i5) {document.form1.i6.value = 0;}
     if (i5 == i4) {document.form1.i5.value = 0;}
     if (i4 == i3) {document.form1.i4.value = 0;}
     if (i3 == i2) {document.form1.i3.value = 0;}
     if (i2 == i1) {document.form1.i2.value = 0;}
     
 // Output the calculated values:
 
    document.form1.Last_Gear.value = i_100;
    document.form1.MT_Time.value = MT_Time;
    document.form1.CVT_Time.value = CVT_Time;
    document.form1.perc_of_MT.value = perc_of_MT;
    document.form1.CVT_more_perf.value = CVT_more_perf;


     
 }
// END IF (i_100 != 0)
    
 } 
// END FUNCTION CALCULATE


function Reset1()
 {
     document.form1.Last_Gear.value = "?";
     document.form1.Mass.value = 1250;
     document.form1.Power.value = 75;
     document.form1.Rpm.value = 5700; 
     document.form1.Tyre_D.value = 0.6;

     document.form1.i1.value = 0.066;
     document.form1.i2.value = 0.095;
     document.form1.i3.value = 0.14; 
     document.form1.i4.value = 0.19;
     document.form1.i5.value = 0.28;
     document.form1.i6.value = 0;
     document.form1.i7.value = 0;
 
    document.form1.MT_Time.value = "?";
    document.form1.CVT_Time.value = "?";
    document.form1.perc_of_MT.value = "?";
    document.form1.CVT_more_perf.value = "?";
 }
 
// END FUNCTION CALCULATE