Problems with adding an "inputbox.dll" to an ExpertAdvisor

[Kreisel]

Hello!

I have a problem with adding an "Inputbox" to my ExpertAdvisor to set an input parameter (Indicator price) by clicking the specific botton ("Button_setINDprice") in the chart.

What I can find in the forum and I´m trying is the following:

..........................................................................................

#include <stdlib.mqh>

#include <WinUser32.mqh>

#property strict

#import "inputbox.dll"

   string InputBox(string,string,string);  // or: string InputBox(string prompt, string title, string default_value);

#import

............

// local variables

int  INDprice=0;

string TXT=IntegerToString(INDprice);

...........

void OnChartEvent(const int id,const long &lparam,const double &dparam,const string &sparam){

   if(id==CHARTEVENT_OBJECT_CLICK){

      if(sparam=="Button_setINDprice"){

         if(ObjectGetInteger(0,sparam,OBJPROP_STATE)==true)  {string INPUT = InputBox("Please set INDIC-Price: ","text...",TXT); INDprice=StrToInteger(INPUT);

...}

..........................................................................................

DLL-Import in MT-Options is allowed. But by clicking the botton always I get the following failure massage:

"Cannot call 'inputbox.dll::InputBox', 'inputbox.dll' is not loaded". "unresolved import function call"

Do I need to attach

"#include <libtrade.mqh>" or/and

"#include <libvisual.mqh>" ???

"libtrade.mqh" doesn´t exist in the direction "terminal\...\MQL4\include" and cannot be find in internet.

Please, anybody can help me?

Thanks!