Masm Error

[Szumith]

Q:
Floating Point Program Consider the equation: x2 + 2x – 8 = 0 .
Write an assembly language program utilizing the floating point instruction set that solves for x using the quadratic formula:
The solution is: x = -4; x = 2
No Global Variable and Loops.

This is the code I have:

TITLE Quadratic Formula
INCLUDE Irvine32.inc

.data
a_prompt BYTE "A:",0
b_prompt BYTE "B:",0
c_prompt BYTE "C:",0
a_co REAL8 ? ;a
a_co_d    REAL8 ? ;double a
ac    REAL8 ? ; a times c
b_co REAL8 ? ;b
b_co_s    REAL8 ? ;b squared
b_co_neg REAL8 ? ;negative b
c_co REAL8 ? ;c
product REAL8 ? ;Holds 4*a*c, then b squared - 4ac, then the sqaure root of that
x_one REAL8 ? ;first x
x_two REAL8 ? ;second x
four REAL8 4.0
two REAL8 2.0
.code
QuadForm PROC
FLD a_co ;push a
FLD two ;push two
FMULP ;multiplies a times 2
FSTP a_co_d ;stores in a_co_d
FLD b_co ;push b
FCHS ;chage sign of ST(0)
FSTP b_co_neg ;stores in b_co_neg
FLD b_co ;push b
FMUL ST(0), ST(0) ;square b
FSTP b_co_s ;and store in b_co_s
FLD c_co ;multiply a and c
FLD a_co
FMULP
FSTP ac ;store in ac
FLD ac
FLD four
FMULP ;multiply ac by 4
FSTP product ;store in product
FLD b_co_s
FLD product ;subtracts product from b squared (b_co_s - product)
FSUB
FSTP product
FLD product ;takes the square root of product, stores back in product
FSQRT
FSTP product

FLD b_co_neg
FLD product
FADD
FDIV a_co_d
FSTP x_one
FLD b_co_neg
FLD product
FSUB
FDIV a_co_d
FSTP x_two
 
 
ret
QuadForm ENDP
main PROC
FINIT
mov edx, OFFSET a_prompt
call WriteString
call ReadFloat
fstp a_co
call Crlf
mov edx, OFFSET b_prompt
call WriteString
call ReadFloat
fstp b_co
call Crlf
mov edx, OFFSET c_prompt
call WriteString
call ReadFloat
fstp c_co
call Crlf
mov edx, 0
call QuadForm
FLD x_one
call WriteFloat
FSTP x_one
call Crlf
FLD x_two
call WriteFloat
FSTP x_two
call Crlf
 
 
exit
main ENDP

END main
But I get these errors:

test.asm(31) : error A2070: invalid instruction operands
test.asm(44) : error A2070: invalid instruction operands
test.asm(49) : error A2070: invalid instruction operands
test.asm(86) : error A2006: undefined symbol : ReadFloat
test.asm(92) : error A2006: undefined symbol : ReadFloat
test.asm(98) : error A2006: undefined symbol : ReadFloat
test.asm(107) : error A2006: undefined symbol : WriteFloat
test.asm(112) : error A2006: undefined symbol : WriteFloat

Could you help me fix the errors?

[jj2007]

Check the FMULP, there is no such instruction. Either FMUL or FMULP ST(n), ST(m)
Besides, an includelib line is missing.