Vaporization pressure UDF property problem?
 

Hi, I write a simple UDF code as in fluent manual by DEFINE_PROPERTY(pres, c,t). The simple code is as below
#include "udf.h"
#include "math.h"

#define A 8.07131
#define B 1730.63
#define C 233.426

DEFINE_PROPERTY(Vapor_pre,c,t)
{
real T;
real P;
T=C_T(c,t)-273;
P=pow(10,A-B/(C+T))*13595.1*9.80665;
return P;
}
The code is complied and loaded successful without any errors, but when I chose the user-define option in the cavitation vaporization pressure tap, in that the name of UDF file is Vapor_pre. After close the option tap, I opened it again - the name of UDF file was not visible in the UDF tap.
I dont know why I got this problem. Could your help me solve this problem?
Thank in advance!

Please help!!!