diff --git a/palindrome_checker.py b/palindrome_checker.py
index c0fdc30..249c1b9 100644
--- a/palindrome_checker.py
+++ b/palindrome_checker.py
@@ -1,7 +1,18 @@
-# palindrome_checker.py
 def is_palindrome(s):
-    return s == s[::-1]
+    # Normalize the string: convert to lower case and filter out non-alphanumeric characters
+    normalized_s = ''.join(char.lower() for char in s if char.isalnum())
+    
+    # Check if the normalized string is equal to its reverse
+    length = len(normalized_s)
+    for i in range(length // 2):
+        if normalized_s[i] != normalized_s[length - 1 - i]:
+            return False
+            
+    return True
 
 if __name__ == "__main__":
-    word = input("Enter a word: ")
-    print(f"{word} is a palindrome: {is_palindrome(word)}")
+    word = input("Enter a word or phrase: ")
+    if word.strip() == "":
+        print("You did not enter a valid string.")
+    else:
+        print(f"'{word}' is a palindrome: {is_palindrome(word)}")