Business Propfile set up email validation fix

Frontend/patient_manager/lib/mih_packages/manage_business/profile_business_add.dart

@@ -200,7 +200,7 @@ class _ProfileBusinessAddState extends State<ProfileBusinessAdd> {
 
   bool validEmail() {
     String text = emailController.text;
-    var regex = RegExp(r'^[a-zA-Z0-9]+@[a-zA-Z.-]+\.[a-zA-Z]{2,}$');
+    var regex = RegExp(r'^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$');
     return regex.hasMatch(text);
   }