Thread: C error?

I'm almost done this code, but I don't know why there is an error...

Code:

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define FILENAME "chill.txt"

/* Define the structure */
struct windchill
{
      int NROWS, NCOLS;
      float NCOLStemp[17], NROWSspeed[21], matrix[21][17];
}

/* FUNCTION PARAMETERS */
float get_airTemp(float airTemp);
float get_windSpeed(float windSpeed);
float get_windChillTemp(struct windchill w1, int fileRow, int fileCol);

int main()
{
      struct windchill w1;
      int i, j, fileRow, fileCol, quit = 0;
      int colCtr, rowCtr, matrixRowCtr, matrixColCtr;
      float windChillTemp;
      float airTemp, windSpeed;
      
      /* Create a pointer of type file */
      FILE *windChillFactorPtr;  
      
      w1.NROWS = 21;
      w1.NCOLS = 17;
      
      /* Open the file */
      windChillFactorPtr = fopen(FILENAME, "r");

      /* If file exists, run the program */
      if(windChillFactorPtr != NULL)
      {
            printf("The file %s exists.\n", FILENAME);             
            
            while(quit != 1)
            {
                    /* Run functions to get the wind speed and temperature */
                    get_airTemp(airTemp);
                    get_windSpeed(windSpeed);

                    /* Read values from air temperature into column array*/            
                    for(j=0; j <= w1.NCOLS - 1; j++)
                    {
                          fscanf(windChillFactorPtr,"%f", &w1.NCOLStemp[j]);
                    }
                    /* Read values from wind speed into row array */
                    for(i=0; i<= w1.NROWS - 1; i++)
                    {
                          fscanf(windChillFactorPtr,"%f", &w1.NROWSspeed[i]);
                    }
                    /* Fill in the matrix */
                    for(i =0; i <= w1.NROWS -1; i++)
                    {
                          for(j =0; j <= w1.NCOLS -1; j++)
                          {
                                fscanf(windChillFactorPtr,"%f", &w1.matrix[i][j]);
                          }
                    }

                    /* Close the file */
                    fclose(windChillFactorPtr);                  
              
              /* Call on function get_windChillTemp */
              windChillTemp = get_windChillTemp(w1, fileRow, fileCol);
              
              /* Print the final answer */
              printf("Wind Chill Temperature = %f\n\n", windChillTemp);      
              
              /* To quit, have user enter 1 */
              printf("Press any key to continue, 1 to quit.\n");
              scanf("%d", &quit);
            }
      }
      
      /* Otherwise, print an error message and quit the program. */
      else
      {
          printf("Error occured when opening the file.");
      }


      system("PAUSE");
      return 0;
}
/*-----------------------------------------------------*/
/* A function to get the air temperature from the user */
float get_airTemp(float airTemp)
{
      printf("Enter the air temperature: \n");
      scanf("%f", airTemp);

      return airTemp;
}
/*-----------------------------------------------------*/
/*    A function to get the wind speed from the user   */
float get_windSpeed(float windSpeed)
{
      printf("Enter the wind speed: \n");
      scanf("%f", windSpeed);
      return windSpeed;
}

float get_windChillTemp(struct windchill w1, int fileRow, int fileCol)
{     
      int k, l, finalK, finalL;
      int airTemp, windSpeed;
      float changeInTemp, windChillTemp;
      
      w1.NROWS=21;
      w1.NCOLS=17;
      
      /* Get air temperature and wind speed from functions above */
      airTemp = get_airTemp(airTemp); 
      windSpeed = get_windSpeed(windSpeed);
  
      /* Round off air temperature and wind speed to a value in the file */
  
      for(k=0; k <= w1.NCOLS; k++)
      {         
                if(airTemp <= w1.NCOLStemp[k] && airTemp >= w1.NCOLStemp[k+1])
                {
                              finalK = k;
                }
      }
  
      for(l=0; l <= w1.NROWS; l++)
      {
                if(windSpeed >= w1.NROWSspeed[l] && windSpeed <= w1.NROWSspeed[l])
                {
                              finalL = l;
                }
      } 
  
      /* List all possible options for rounding of numbers in the matrix */
  
      if(abs(w1.NCOLStemp[finalK] - airTemp) < abs(w1.NCOLStemp[finalK+1] - airTemp) && abs(w1.NROWSspeed[finalL] - airTemp) < abs(w1.NROWSspeed[finalL+1] - airTemp))
      {
                changeInTemp = w1.matrix[finalK][finalL];
      }
      else if(abs(w1.NCOLStemp[finalK] - airTemp) > abs(w1.NCOLStemp[finalK+1] - airTemp) && abs(w1.NROWSspeed[finalL] - airTemp) < abs(w1.NROWSspeed[finalL+1] - airTemp))      
      {
                changeInTemp = w1.matrix[finalK+1][finalL] ;
      }
      else if(abs(w1.NCOLStemp[finalK] - airTemp) < abs(w1.NCOLStemp[finalK+1] - airTemp) && abs(w1.NROWSspeed[finalL] - airTemp) > abs(w1.NROWSspeed[finalL+1] - airTemp))
      {
                changeInTemp = w1.matrix[finalK+1][finalL+1];
      }
      else                                       
      {
                changeInTemp = w1.matrix[finalK][finalL+1];
      }
  
      /* To find wind chill temperature */
      windChillTemp = airTemp - changeInTemp;
      return windChillTemp;

  system("PAUSE");	
}
/*-----------------------------------------------------*/

The error is in line 15:

Code:

float get_airTemp(float airTemp);

It says: two or more data types in declaration of 'get_airTemp'

There is also an error without a line number, that says:

[Build Error] n\make.exe ***[Untitled1.o] Error 1


Does anyone know how to get rid of this?