Hi there

Ok, basically I'm pretty new to C and have created a mashed-together program using different elements from different existing programs:

Code:
#include <stdio.h>

#define ALPHABET_TOTAL 26                    /* Defines the total number of letters in the alphabet */

main()
{
      int text[ALPHABET_TOTAL] = {0},        /* Creates an array of size 26, acting as counters initialized as 0*/    
          text_input,                        /* Reads in the text input as characters */
          ASCII_count,                       /* ASCII number of the letters in the alphabet */
          alpha;                             /* boolean flag which turns to 0 (false) in case of a non-alpha character */
      
/* Setting values to 0 */
      
      text_input = 0;
      ASCII_count = 0;
      alpha = 0;


/* Get input - this needs to change!! */

      FILE *userfile; /* declares file pointer */

      printf("Enter file name to load: ");

      scanf("%s", filename);
 
      userfile = fopen("%s", "r");

      
 /* Perform text analysis*/    


      while( text_input != EOF )
      {
        alpha = 1;
        text_input = getchar();    
        
/* If input is alphabetical, convert to a number 0-25 so that it can be used as a locator along the array */
      
      if(text_input >= 'a' && text_input <= 'z')
       text_input -= 'a';
      else if(text_input >= 'A' && text_input <= 'Z')
       text_input -= 'A';

/* Non-alphabetical character, set the alpha flag to false */
    
      else
       alpha = 0;

/* Increment the appropriate counter in the text array as long as the character is alphabetical */
    
      if(alpha)
       text[text_input]++;
     }
    
/* Display results */
    
    for (ASCII_count; ASCII_count <= 25; ASCII_count++)
     printf("\nTotal %c or %c: %d", ASCII_count + 'a', ASCII_count + 'A',text[ASCII_count]);
}
As you can probably tell, I'm trying to prompt the user for a file name then conduct a letter frequency analysis on the text contained in said file.
What's wrong with what I've got? I'm guessing it's the code prompting for the user file.

Also, If I wanted to add in a counter to keep track of the total number of characters in the text, whereabouts in the various loops would it go?

Any help would be greatly appreciated. I really want to get to grips with C!