diff --git a/bintree.c b/bintree.c
index d4a26ff..079cad5 100644
--- a/bintree.c
+++ b/bintree.c
@@ -13,25 +13,46 @@
 TreeNode *addToTree(TreeNode *root, const void *data, size_t dataSize, CompareFctType compareFct, int *isDuplicate)
 {
 	if (root == NULL){
-		Treenode *node = malloc(sizeof(Treenode));
-		if (!node)
+		TreeNode *node = malloc(sizeof(TreeNode));
+		if (!node){
 			return NULL;
+		}
 
-		node->date = malloc(dataSize)
-		if (!node->data)
+		node->data = malloc(dataSize);
+		if (!node->data){
+			free (node);
+			return NULL;
+		}
+
+		memcpy(node->data, data, dataSize);
+
+		node->left = NULL;
+		node->right = NULL;
+		return node;
+	}
+
+	int cmp = compareFct(data, root->data);
+
+	if (cmp == 0){
 
 
+		if (isDuplicate == NULL){
+			root->right = addToTree(root->right, data, dataSize, compareFct, NULL);
+			return root;
+		}
 
-
-	TreeNode *root = malloc(sizeof(TreeNode));
-
-	function createNode(data)
-		root = new TreeNode;
-		node -> data = data;
-		node -> left = NULL;
-		node -> right = NULL;
+		*isDuplicate = 1;
 		return root;
+	}
 
+
+	if (cmp < 0){
+		root->left = addToTree(root->left, data, dataSize, compareFct, isDuplicate);
+	}
+	else{
+		root->right = addToTree(root->right, data, dataSize, compareFct, isDuplicate);
+	}
+	return root;
 }
 
 // Iterates over the tree given by root. Follows the usage of strtok. If tree is NULL, the next entry of the last tree given is returned in ordering direction.
@@ -45,11 +66,27 @@ void *nextTreeData(TreeNode *root)
 // Releases all memory resources (including data copies).
 void clearTree(TreeNode *root)
 {
+	if (root == NULL){
+		return;
+	}
 
+	clearTree(root->left);
+	clearTree(root->right);
+
+	free(root->data);
+	free(root);
 }
 
 // Returns the number of entries in the tree given by root.
 unsigned int treeSize(const TreeNode *root)
 {
+	if (root == NULL){
+		return 0;
+	}
 
+	unsigned int kidsleft = treeSize(root->left);
+	unsigned int kidsright = treeSize(root->right);
+ 	unsigned int size = kidsleft + kidsright + 1;
+
+	return size;
 }
\ No newline at end of file