Error message displayed on all my forms

I have three forms on my page, one for update personal details(Names) Second one for update password and last one for updates user devices.

When user clicks on submit for a certain form maybe for change password, the message is display on all the forms that password is successfully changed. I want the message to be displayed on that form that was updated.

The code

 <input type="submit" id="submit" value="Update Password" name="changepassword" style="margin-left:70px;"/>

 <input type="submit" id="submit" value="Update" name="changepersonal"/>

   <input type="submit" id="submit" value="Update"  name="updatedevice"  style="margin-left: 250px;" />