求助（我的第一篇文章）

今天刚刚发布这篇文章，也是为了征求各位大佬，下面的这个是我做的一个vb小程序，它可以执行二元一次方程的算法

Private Sub Command1_Click()
Dim a, b, c As Integer
a = Val(Text1.Text)
b = Val(Text2.Text)
c = Val(Text3.Text)
If Not IsNumeric("a,b,c") Then
          MsgBox "你输入的不是纯数字"
          Else
          Text1.Text = ""
          Text2.Text = ""
          Text3.Text = ""
          Text1.Text = ""
          End If
dt = b ^ 2 - 4 * a * c
Select Case dt
     Case Is >= 0
     a1 = -b + Sqr(dt) / 2 * a
     a2 = -b - Sqr(dt) / 2 * a
     Label1.Caption = "x1为：" & a1 & "取整为：" & Val(Fix(a1)) & Chr(13) & Chr(10) & "x2为:" & a2 & "取整为：" & Val(Fix(a2))
     Case Else
     Label1.Caption = "这个方程在实数范围内无解"
     End Select
End Sub

Private Sub Form_Load()
Text1.Text = ""
Text2.Text = ""
Text3.Text = ""
Command1.Caption = "二元一次方程为"
Label1.Caption = ""
End Sub