# MBUTTONPAN System Variable [GstarCAD 2020](Help%20System/GSTARCAD/2020/Index.md) → [System Variables](Help%20System/GSTARCAD/2020/System%20Variables/(System%20Variables).md) → [M](Help%20System/GSTARCAD/2020/System%20Variables/M/(M).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 --- ## Other versions with matching text [GstarCAD 2016](../../../2016/System%20Variables/M/MBUTTONPAN%20System%20Variable.md) · [GstarCAD 2017](Help%20System/GSTARCAD/2017/System%20Variables/M/MBUTTONPAN%20System%20Variable.md) · [GstarCAD 2018](Help%20System/GSTARCAD/2018/System%20Variables/M/MBUTTONPAN%20System%20Variable.md) · [GstarCAD 2019](Help%20System/GSTARCAD/2019/System%20Variables/M/MBUTTONPAN%20System%20Variable.md) · [GstarCAD 2021](Help%20System/GSTARCAD/2021/System%20Variables/M/MBUTTONPAN%20System%20Variable.md) · [GstarCAD 2022](Help%20System/GSTARCAD/2022/System%20Variables/M/MBUTTONPAN%20System%20Variable.md)