twSetMRTime( lRelease )
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     Set the a logical default whether to wait for a button release
     when on a Hot Spot defined with TSDWIN mouse supported functions.
     It is set initially to FALSE. In most cases, the default will be
     found sufficient.

       Arguments:

     lRelease - 'L' Logical to indicate whether  a button release is
                    required by TSDWIN mouse supported functions.

       Return:

     Old value of lRelease.

       Example:

     twSetMRTime( .F. )