sele 用户口令表  inname=alltrim(thisform.pageframe1.page1.text1.value) inpswd=alltrim(thisform.pageframe1.page1.text2.value) set order to 账号 seek inname if !found() cMessageTitle='设备管理系统' cMessageText='用户名错误，请重新输入' nDialogType=4+32 nAnswer=messagebox(cMessageText,nDialogType,cMessageTitle) do case case nAnswer=6 thisform.pageframe1.page1.text1.value="" thisform.pageframe1.page1.text1.setfocus case nAnswer=7 messagebox("请勿偷窃他人资料",48,"警告") thisform.release endcase else if allt(密码)!=inpswd  cMessageTitle='设备管理系统' cMessageText='密码错误，请重新输入' nDialogType=4+32 nanswer=messagebox(cMessageText,nDialogType,cMessageTitle) do case case nAnswer=6 if flag<2 thisform.pageframe1.page1.text2.value="" thisform.pageframe1.page1.text2.setfocus flag=flag+1 else messagebox("请勿偷窃他人资料",48,"警告") thisform.release endif case nAnswer=7 messagebox("请勿偷窃他人资料",48,"警告") thisform.release endcase else thisform.release par1=inname do 菜单2.mpr endif endif

下次提问，请注意形式，请写成这样
sele 用户口令表  
inname=alltrim(thisform.pageframe1.page1.text1.value)
inpswd=alltrim(thisform.pageframe1.page1.text2.value)
set order to 账号
seek inname
if !found()
    cMessageTitle='设备管理系统'
    cMessageText='用户名错误，请重新输入'
    nDialogType=4+32
    nAnswer=messagebox(cMessageText,nDialogType,cMessageTitle)
    do case
        case nAnswer=6
            thisform.pageframe1.page1.text1.value=""                  
    thisform.pageframe1.page1.text1.setfocus
        case nAnswer=7
            messagebox("请勿偷窃他人资料",48,"警告")
            thisform.release
    endcase
else   if allt(密码)!=inpswd  
    cMessageTitle='设备管理系统'
    cMessageText='密码错误，请重新输入'
    nDialogType=4+32
    nanswer=messagebox(cMessageText,nDialogType,cMessageTitle)
    do case
        case nAnswer=6
            if flag<2
                thisform.pageframe1.page1.text2.value=""              
                thisform.pageframe1.page1.text2.setfocus
                flag=flag+1
            else
                messagebox("请勿偷窃他人资料",48,"警告")
                thisform.release
            endif
        case nAnswer=7
            messagebox("请勿偷窃他人资料",48,"警告")
            thisform.release
    endcase
    else
        thisform.release
        par1=inname
        do 菜单2.mpr
    endif
endif

不输入密码，字符串为""，它与任何字符串=比较均为真。使用==比较吧。

把这个
if allt(密码)!=inpswd  

改成
if empty(allt(密码)) or allt(密码)!=inpswd  
试试

同意二、三楼。