用VF解一元二次方程

* 求一元二次方程的根
clear
set talk off
input "请输入A值:" to a
input "请输入B值:" to b
input "请输入C值:" to c
if b*b-4*a*c>=0
x1=alltrim(str((-b+(b*b-4*a*c)^(1/2))/(2*a)))
x2=alltrim(str((-b-(b*b-4*a*c)^(1/2))/(2*a)))
else
x1=alltrim(str(-b/(2*a),6,2))-"+"-alltrim(str((4*a*c-b*b)^(1/2)/(2*a),8,2))-"i"
x2=alltrim(str(-b/(2*a),6,2))-"-"-alltrim(str((4*a*c-b*b)^(1/2)/(2*a),8,2))-"i"
endif
?"x1=",x1
??" x2=",x2
set talk on
return

clear
set talk off
input "请输入A值:" to a
input "请输入B值:" to b
input "请输入C值:" to c
if b*b-4*a*c>=0
x1=alltrim(str((-b+(b*b-4*a*c)^(1/2))/(2*a)))
x2=alltrim(str((-b-(b*b-4*a*c)^(1/2))/(2*a)))
else
x1=alltrim(str(-b/(2*a),6,2))-"+"-alltrim(str((4*a*c-b*b)^(1/2)/(2*a),8,2))-"i"
x2=alltrim(str(