spell checker with BST

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
 
 
//CONSTANTS 
#define wrdlen 48 
#define linelen 1024
 
 
// A struct representing a node in a binary search tree
 
struct treenode
{
    // The contents of the node
char word[wrdlen];
	// Links to the node's left and right children
struct treenode* left;
struct treenode* right;
};
 
// Adds a new node to the tree. Duplicates are disallowed. Returns 1 if a
// new node was added, returns 0 if newdata was already in the tree
int insert(struct treenode** root, char newword[wrdlen])
{
    // If we've reached the right place to insert, create a new node and add it in
	if( (*root) == NULL)
	{
		(*root) = (struct treenode*)malloc(sizeof(struct treenode));
        strcpy((*root)->word,newword);
		(*root)->left = NULL;
		(*root)->right = NULL;
		return 1;
	}
    // Otherwise, search for the correct place to insert
 
	if(strcmp(newword,(*root)->word)<0)
	{
		return insert( &((*root)->left), newword);
	}
 
	else if(strcmp(newword,(*root)->word)>0)
	{
		return insert( &((*root)->right), newword);
	}
// If the new data is neither less than nor greater than the the data at
// the current node, it must be equal, and duplicates are not allowed
	else
	return 0;
}
 
// Returns 1 if target is in the tree and 0 otherwise
int search(struct treenode* root, char target[wrdlen])
{
    // An empty tree contains nothing, much less target
	if(root == NULL)
		return 0;
	// If the current node is what we're looking for, we've found it 
 
	if(strcmp(root->word,target) == 0)
		return 1;
    // If what we're looking for is smaller than this node, it must be in
    // the left subtree if it exists
	if(strcmp(target,root->word) < 0)
		return search(root->left, target);
	// Similarly, if the target is greater than this node, it can only be in
    // the right subtree
	else
	return search(root->right, target);
}
 
// An iterative version of the search algorithm
int searchiterative(struct treenode* root, char target[wrdlen])
{
	struct treenode* crnt = root; 
	// Keep descending through the tree until we reach the bottom or find what
	// we're looking for
	while(crnt != NULL && strcmp(crnt->word,target)!=0)
	{
		if(strcmp(target,crnt->word)>0)
		crnt = crnt->left;
 
		else
		crnt = crnt->right;
	}
	// If we reached the bottom of the tree, then the target isn't present,
	// otherwise we found what we're looking for
	if(crnt == NULL)
		return 0;
	
	else
		return 1;
}
 
void spellcheck(struct treenode* root, char *token, int line)
{
    //capital letters are from 65 -> 90
    //lowercase letters are from 97-122  
    if(search(root, token))//if you find it normally then 
      return;
 
     else if(token[0] >= 65 && token[0] <= 90)
     {
          token[0] = token[0] + 32;
          if(search(root, token))
             return;
 
          else
          {   
              token[0] = token[0] - 32;
              printf("Line %d: %s\n", line, token); 
              return;
          }
     }
 
     else
     {
         printf("Line %d: %s\n", line, token);
         return;
     }
}
 
 
int main(void)
{
    FILE *ifp; //dictionary file
    FILE *scfp; //file to be spellchecked
    char infile[wrdlen]; //"words.txt";
    char Tinfile[wrdlen]; //"test.txt"; //test file
    int valid = 0;
    struct treenode* root;
    char newword[wrdlen];
    root = NULL;
    int i = 0;
    char str[linelen];
    char delims[] = ("~!@#$%^&*()-_=+[]{}\\|;:\'\",.<>/?\n\r\t ");
    root = NULL;   
 
    //ask the user for the dictionary file
    while(!valid)
    {
         printf("Please enter the name of the dictionary file you wish to access\n");
         scanf("%s", infile);
         ifp = fopen(infile, "r");         
 
         if(ifp == NULL)
           printf("sorry, could not find that file!\n");
         else
         {   
             valid = 1;
             printf("Reading file now.........\n");
         }
    }    
    valid = 0;
    //read in all the words and place them into a BST
    while(!feof(ifp))
    {
        fscanf(ifp, "%s ", newword);
        insert(&root, newword);
    }   
 
    //ask the user for the file to be spellchecked
    while(!valid)
    {
		printf("what is the name of the file you would like to spellcheck?\n");
		scanf("%s", Tinfile);
		scfp = fopen(Tinfile, "r");
		if(scfp == NULL)
           printf("sorry, could not find that file!\n");
		else
		{   
             valid = 1;
             printf("Reading file now.........\n");
		}
    }    
 
    printf("The following words were not recognized: \n");    
 
    for(i = 1; !feof(scfp); i++)
    {
     // start my spellchecking algorithm here
		fgets(str, linelen, scfp);
		char *token;
		token = strtok(str, delims);          
 
		while( token != NULL ) 
		{
			spellcheck(root, token, i);    
			token = strtok( NULL, delims );
	    }    
    }
	system("PAUSE");
    return; 
}