simplified the CAESAR problem

this if statement does not seem to work
please help me fix the bug.

Code:

k = 0;

for(i = 0;i < l;i++);
  {
   if( (ascii[i] == 32) || (i == (l - 1)) )
    {
                                           //  printf("%d\n",i);
      
      while( (k <= i) && ascii[k] >= 97 && ascii[k] <= 122)
      {
       ascii[k] = ascii[k] + 3;
       
       secret[k] = ascii[k];
      
       k = k + 1; 
      
      }
    k = i + 1;
    
    }
        
  }