在pb中使用SETFILTER进行两个条件以上筛选总报错

string ls_condition1
string ls_condition2
string ls_condition

ls_condition1="sfsc='1'"
ls_condition2="upper(jxbh) like '%"+upper(sle_1.text)+"%'"
if ls_condition2='' then
    if ls_condition1<>'' then
        ls_condition=ls_condition1
    end if
else
    if ls_condition1<>'' then
        ls_condition=ls_condition1+ ' and '+ls_condition2
    else
        ls_condition=ls_condition2
    end if
   
end if
//ls_condition=string(ls_condition)
messagebox(' ',ls_condition)
dw_1.setfilter(ls_condition)
报错EXPRESS IS NOT VALID