# MBUTTONPAN System Variable [GstarCAD 2027](Help%20System/GSTARCAD/2027/Index.md) → [System Variables](Help%20System/GSTARCAD/2027/System%20Variables/(System%20Variables).md) **Function Description:** The MBUTTONPAN system variable is used to control the behavior of the third button or wheel on the pointing device. | | | | --- | --- | | Type | Integer | | Saved in | Registry | | Initial value | 1 | | Range | 0,1 | **System Variable Value:** **0:** support definition operations in custom files **1:** support pan operation when holding and drag the button or wheel --- [Original help](https://www.gstarcad.net/help/GstarCAD_2027_en-US/detail/systemVariables/MBUTTONPAN.html) · © Gstarsoft Co., Ltd.