Update up_gr.html

up_gr.html

@@ -87,7 +87,16 @@
             const reader = new FileReader();
             reader.onload = async function(event) {
                 const text = event.target.result;
-                const chatIds = text.split('\n').map(line => line.trim() + '@c.us').filter(line => line);
+                const chatIds = text.split('\n')
+                                    .map(line => line.trim())
+                                    .filter(line => line && /^\d+$/.test(line))
+                                    .map(line => line + '@c.us');
+
+                if (chatIds.length === 0) {
+                    alert('The file must contain valid phone numbers.');
+                    return;
+                }
+
                 const payload = {
                     groupName: groupName,
                     chatIds: chatIds