RTD PT100 solved almost

[syntax = c]

//Negative Temperatures (-200 degree C to 0 degree C)
           if (pt100_r1 < 100.00) {
              /*
              x = r = 72.33
              xo = ro = 18.52
              x1 = r1 = 100
              y= t = ?
              y0 = t0 = -200
              y1 = t1 = 0
              t = t0 + ((r-r0)t1 - (r-ro)t0) / (r1-r0)
              */
              r = pt100_r1;
              r0 = 18.52;
              r1 = 98.44;
              t0 = -200.00;
              t1 = 0.0;
              t = t0 + ((r-r0)*t1 - (r-r0)*t0) / (r1-r0);
              pt100_t1 = t;
           }

[/syntax]

void Display_Temp(void)
{
  ch = (tlong / 1000) % 10;
   //Lcd_Out(1,3,"Tmp");
  Lcd_Chr(row,position,48+ch);          // Write result in ASCII format
  ch = (tlong / 100) % 10;
  Lcd_Chr_Cp(48+ch);          // Write result in ASCII format
  ch = (tlong / 10) % 10;
  Lcd_Chr_Cp(48+ch);          // Write result in ASCII format
  Lcd_Chr_CP('.');
  ch = (tlong ) % 10;     // Extract hundreds of millivolts
  Lcd_Chr_CP(48+ch);           // Write result in ASCII format
  Lcd_Chr_CP('/');
  Delay_ms(100);
}
/*******************************************************************************/
/****************************  Get_Temp   **********************************/
/*******************************************************************************/
 void Get_Temp(void)
 {
  ADCON0 = 0x01;// select channel 0
  for(i=0;i<5;i++)
  {
   adc_rd0 = ADC_Read(0);
   sample[i] = adc_rd0;
   Delay_ms(50);
  }
  average = 0;
  for(i=0;i<5;i++)
  {
   average += sample[i];
  }
  average/=5;

  Temp = (float)average*1.00/1024.00;// using 1V ref.
  Temp = Temp/1.4; // found that PT100 changes voltage of 1.4mV/C with a voltage divider with 1K.
  Lcd_Out(1,1,"TEMP<");
  Lcd_Chr_Cp(223);
  Lcd_Out(1,7,"C>");
  tlong = Temp*1000;
  row = 1;
  position = 9;
  Display_Temp();
 }