could not convert... from void to bool

Hi guys, overview of the situation:
-I am working with GUISlice.
-I have multiple pages
-Each page has some kind of different function.
-I would like the neccesary code for each page to only run when that particular page is being viewed.

Something like this:

If (you're viewing this page) {
do stuff ;
do some more stuff;
Maybe a delay;
}

Im pretty new to all of this, there are certain aspects of coding that I dont completley understand, and sometimes I ask some dumb questions.

Anyway here is what I tried

if (gslc_SetPageCur(&m_gui, E_PG3)){
  TS_NTC_103 sensor(0.11,10);
float Temp = sensor.getTemp(analogRead(36));


 gslc_ElemXRingGaugeSetVal(&m_gui, m_pElemXRingGauge1 ,Temp );

char                acTxt[MAX_STR];
snprintf(acTxt,MAX_STR,"%f",Temp);

  gslc_ElemSetTxtStr(&m_gui,m_pElemXRingGauge1,acTxt);
delay (500);
}

The only place in the code that I can see that gives some indication of what page has been selected or is being viewed is this:

bool CbBtnCommon(void* pvGui,void *pvElemRef,gslc_teTouch eTouch,int16_t nX,int16_t nY)
{
  // Typecast the parameters to match the GUI and element types
  gslc_tsGui*     pGui     = (gslc_tsGui*)(pvGui);
  gslc_tsElemRef* pElemRef = (gslc_tsElemRef*)(pvElemRef);
  gslc_tsElem*    pElem    = gslc_GetElemFromRef(pGui,pElemRef);

  if ( eTouch == GSLC_TOUCH_UP_IN ) {
    // From the element's ID we can determine which button was pressed.
    switch (pElem->nId) {
//<Button Enums !Start!>
      case E_ELEM_IMAGEBTN3:
        gslc_SetPageCur(&m_gui, E_PG2);
        break;
      case E_ELEM_IMAGEBTN4:
        gslc_SetPageCur(&m_gui, E_PG4);
        break;
      case E_ELEM_IMAGEBTN1:
        gslc_SetPageCur(&m_gui, E_PG3);
        break;
      case E_ELEM_IMAGEBTN2:
        gslc_SetPageCur(&m_gui, E_PG5);
        break;
      case E_ELEM_IMAGEBTN6:
        gslc_SetPageCur(&m_gui, E_PG_MAIN);
        break;
      case E_ELEM_IMAGEBTN7:
        gslc_SetPageCur(&m_gui, E_PG_MAIN);
        break;
      case E_ELEM_IMAGEBTN8:
        gslc_SetPageCur(&m_gui, E_PG_MAIN);
        break;
      case E_ELEM_BTN1:
        break;
      case E_ELEM_BTN2:
        break;
      case E_ELEM_BTN3:
        break;
      case E_ELEM_BTN5:
        break;
      case E_ELEM_IMAGEBTN9:
        gslc_SetPageCur(&m_gui, E_PG_MAIN);
        break;
//<Button Enums !End!>
      default:
        break;
    }
  }
  return true;
}

The error message i get is :

\Arduino\tiretool\tiretool.ino: In function 'void loop()':
tiretool:131:22: error: could not convert 'gslc_SetPageCur((& m_gui), 2)' from 'void' to 'bool'
   if (gslc_SetPageCur(&m_gui, E_PG3)){
                      ^
.....

exit status 1
could not convert 'gslc_SetPageCur((& m_gui), 2)' from 'void' to 'bool'

Can someone please tell me if I am on the right track? Maybe a brief explanation on why its not working and how to implement something like this properly?

Thanks

According to the documentation gslc_SetPageCur sets the current page. It does not return anything, hence the error message.

Also, according to the documentation you can get the current page using the following call:

int gslc_GetPageCur (gslc_tsGui ∗ pGui )

You can use the return value to compare with a page value.