我编写的一个小软件，用于梯形螺纹的精度设计，其中外螺纹的大径下偏差能够从表中查出来，为何小径下偏差却显示不出来。求高手指导，必定重谢
如图
最下面那个0应该显示的是查表的数值，那个文本框对应n15

程序如下：public n14,n15,n16,n18,n17,n19，n20
n14=0

n16=0
n18=0
n17=0
n19=0
n20=0


if thisform.optiongroup1.value=1
       n6=1
   else
       n6=2
endif

select xhn2 from xhcd07 into array dd where (xhcd07.jbdj1<n9) and (xhcd07.jbdj2>=n9) and(xhcd07.pitch=n10)
n8=dd

if val(thisform.text1.value)>n8
    n7=2
  else
    n7=1
endif

if empty(thisform.text1.value)
     messagebox("请输入旋合长度数值",0+16,"提示")
     thisform.text1.value=""
     thisform.text1.setfocus
  else
  
dime  wzjgc(1), wxjgc(1), pce(1) ,wdjgc(1)
select t4 from wdg03 into array wdjgc where (wdg03.pitch=n10)  


    do case
    case n6=1 and n7=1
       n13=7
       select e7 from wxg04 into array wxjgc where (wxg04.jbdj1<n9) and (wxg04.jbdj2>=n9) and (wxg04.pitch=n10)
       select wees from zjp01 into array pce where (zjp01.pitch=n10)
       select t7 from wzg06 into array wzjgc where (wzg06.jbdj1<n9) and (wzg06.jbdj2>=n9) and (wzg06.pitch=n10)     
       n16=0
       n18=0-wdjgc(1)
       n14=0
       n15=0-wxjgc(1)
       n17=pce(1)
       n20=wzjgc(1)
       n19=n17-n20
      
      
     
     case n6=1 and n7=2
       n13=8
       select e8 from wxg04 into array wxjgc where (wxg04.jbdj1<n9) and (wxg04.jbdj2>=n9) and (wxg04.pitch=n10)
       select wees from zjp01 into array pce where (zjp01.pitch=n10)
       select t8 from wzg06 into array wzjgc where (wzg06.jbdj1<n9) and (wzg06.jbdj2>=n9) and (wzg06.pitch=n10)     
       n16=0
       n18=0-wdjgc(1)
       n14=0
       n15=0-wxjgc(1)
       n17=pce(1)
       n20=wzjgc(1)
       n19=n17-n20
      
    case n6=2 and n7=1
       n13=8
       select c8 from wxg04 into array wxjgc where (wxg04.jbdj1<n9) and (wxg04.jbdj2>=n9) and (wxg04.pitch=n10)
       select wces from zjp01 into array pce where (zjp01.pitch=n10)
       select t8 from wzg06 into array wzjgc where (wzg06.jbdj1<n9) and (wzg06.jbdj2>=n9) and (wzg06.pitch=n10)     
       n16=0
       n18=0-wdjgc(1)
       n14=0
       n15=0-wxjgc(1)
       n17=pce(1)
       n20=wzjgc(1)
       n19=n17-n20
              
    case n6=2 and n7=2
       n13=9
       select c9 from wxg04 into array wxjgc where (wxg04.jbdj1<n9) and (wxg04.jbdj2>=n9) and (wxg04.pitch=n10)
       select wces from zjp01 into array pce where (zjp01.pitch=n10)
       select t9 from wzg06 into array wzjgc where (wzg06.jbdj1<n9) and (wzg06.jbdj2>=n9) and (wzg06.pitch=n10)     
       n16=0
       n18=0-wdjgc(1)
       n14=0
       n15=0-wxjgc(1)
       n17=pce(1)
       n20=wzjgc(1)
       n19=n17-n20      
endcase

thisform.release
do form bd7b.scx
endif