444ed39d_rePoint_2010___Charlie_Holland__Description
[Property] autoSize [Data type] boolean (true/false) [Default value] true [Description] 
Determines whether the dialog should be automatically sized to fit within the parent browser window. Where a value has been set for width or height, this value is deemed to be false regardless of the actual setting.
Using the Dialog framework in SharePoint 2010 » Charlie Holland
Description