关于VB的题 从键盘输入a,b,c,求一元二次方程Ax方 +bx+c=0 的根,如果无实根,则输出“没有实数根”

Private Sub Command1_Click()
a = Val(Text1.Text)
b = Val(Text2.Text)
c = Val(Text3.Text)
If b ^ 2 - 4 * a * c < 0 Then
Text4.Text = "方程没有实数根"
ElseIf b ^ 2 - 4 * a * c = 0 Then
x = -b / (2 * a)
Text4.Text = "方程有一个根:" & x
Else
X1 = (-b + Sqr(b ^ 2 - 4 * a * c)) / (2 * a)
X2 = (-b - Sqr(b ^ 2 - 4 * a * c)) / (2 * a)
Text4.Text = "方程有两个根：" & X1 & "和" & X2
End If
End Su