Add getUsernameFromCookie function

owe.js

@@ -55,6 +55,24 @@ async function loadConfig() {
 	});
 }
 
+function getUsernameFromCookie() {
+    // Split the document.cookie string into individual cookie key-value pairs
+    var cookies = document.cookie.split(';').map(cookie => cookie.trim());
+
+    // Loop through the cookies to find the 'owe_user' cookie
+    for (var i = 0; i < cookies.length; i++) {
+        var cookie = cookies[i];
+        if (cookie.startsWith('owe_user=')) {
+            // Extract the username from the 'owe_user' cookie
+            return decodeURIComponent(cookie.substring('owe_user='.length));
+        }
+    }
+
+    // Return null if the 'owe_user' cookie is not set
+    return null;
+}
+
+
 function onReloadClicked() {
 	loadSentences();
 	document.querySelector("#but-reload").style.visibility = "hidden";