if (thisform.ym>=thisform.command2.top and thisform.ym<=thisform.command2.top+thisform.command2.height);
and (thisform.xm>=thisform.command2.left and thisform.xm<=thisform.command2.left+thisform.command2.width)
&&&&鼠标位置在返回按钮的区间内
else
if empt(allt(this.value))
=messagebox('不能为空',16,'提示')
retu .f.
endi
endi