Password Change with c - script

Dear Experts,

I made Current user password modification screen.
some days ago, I remember it works well.
But now a days I get error which message is 'No Password!, line 76'
You can fined the screen-shot in attached jpg file.

Following C-Script will proceed when click save button.

======================================= Script =========================
#include "apdefap.h"
void OnLButtonDown(char* lpszPictureName, char* lpszObjectName, char* lpszPropertyName, UINT nFlags, int x, int y)
{
#pragma option(mbcs)

#pragma code("usegen.lib")
#pragma code("usegen.dll")
#include "PWRT_api.h"
#include "usegenap.h"
#pragma code()

char* strUser;
char* strPW;
char* strNPW;
char* strNPW1;
int excute;
int iReturn;

CMN_ERROR error;
memset(&error,0,sizeof(CMN_ERROR));
strUser = GetTagChar("@CurrentUserName"); //Return-Type: char*
strPW = GetInputValueChar("MAINTENANCE_CPW.Pdl","CurrentPW"); //Return-Type: char*

strNPW = GetInputValueChar("MAINTENANCE_CPW.Pdl","NewPW"); //Return-Type: char*
strNPW1 = GetInputValueChar("MAINTENANCE_CPW.Pdl","NewPW1"); //Return-Type: char*

if(strcmp(GetTagChar("@CurrentUser"),"")==0)
{
// No Current User
excute = 3;
}
else
{
if(strcmp(strNPW, strNPW1)==0)
{
// Change Password
PWGENConnect("JOHN-PC1",NULL);//Return-Type: BOOL
excute=PWGENChangePassword(strUser,strPW,strNPW,&error) ;
}
else
{
// Not same with two new Password
excute = 2;
}

}

if (excute==1)
{
// Success to Change
SetTagBit("ChangPWStat",0);
SetTagChar("ChangPWError","Changed Well"); //Return-Type: BOOL
}
else if(excute ==2)
{
// diffrent new passwords
SetTagBit("ChangPWStat",1);
SetTagChar("ChangPWError","New Password and Confirm Password are not same"); //Return-Type: BOOL
}
else if(excute ==3)
{
// no Current User
SetTagBit("ChangPWStat",1);
SetTagChar("ChangPWError","Login First with Clikcing 'Ctrl + L'"); //Return-Type: BOOL
}
else
{
// Error Occured
SetTagBit("ChangPWStat",1);
SetTagChar("ChangPWError",error.szErrorText); //Return-Type: BOOL
}
PWGENDisconnect(NULL);
}
=============================== End Script ===============================

WinCC Version is 7.0 sp 2.
But It updated with Update5ForWinCCV7sp2

Please tell me if you can find my fault in my script.

Thanks in advance~

Jongbom Yu