Unable to close the form personalization message window with single click

Hi,

We are using  the R12.1.3 version and as per requirement we need to display a message on Invoice distribution form, if the liability account segment1 value (from Invoice headers) is not equals to the GL string segment1 value (which is from Invoice distributions), we need to display a  message which will help users to correct the GL string accordingly, to achieve this we have used the

‘WHEN-VALIDATE-RECORD’ trigger with required condition and able to display the text message on Invoice distribution form.

The problem which we are facing is we are unable to close the message window by clicking on ‘OK’ button(which is available on message window) with single click. When we click on twice on ‘OK’ button then only it is allowing us to close the message window on the distribution form.