msgbox vbyesno

Hi

I am struggling to work out how to get the vbyesno statements from a msgbox to work for my user defined function below.
the statements are

MsgBox "You have selected to use " & N & " days" & " of data" _
& " and you have selected a price range of:" & PriceRange.Address(external:=True) & "," & " is this OK?", vbYesNo
If MsgResult = vbNo Then End

and

msgBox "Would you like to use the annualised volatility to calculate the sharpe ratio of the selected range?", vbYesNo
If MsgResult = vbNo Then Exit Function


However both the do not work as the function keeps running. Please how can i get them to work and end the procedure once no is clicked? coding below.

Thanks

Function StkVol(N, PriceRange)

'-----------------Declaring Variables---------------------------------'

Dim i, DlyRet()                                     'Daily return at time i
ReDim DlyRet(N - 1)                              'Dynamic range dependent on user input N
Dim MsgResult As VbMsgBoxResult

'*****************Check Input Data *************************************'

MsgBox "You have selected to use " & N & " days" & " of data" _
& " and you have selected a price range of:" & PriceRange.Address(external:=True) & "," & " is this OK?", vbYesNo
If MsgResult = vbNo Then End
   
MsgBox "Please note that prices must be arranged from newest to oldest"

'*****************Calculation********************************************'
'Calculate daily returns
For i = 1 To N - 1   'Specifying price range dependent on user input N

    DlyRet(i) = Log(PriceRange(i) / PriceRange(i + 1)) 'In VBA Log function returns the natural logarithm of a number
Next

'Calculate and annualize standard deviation
StkVol = Application.StDev(DlyRet) * Sqr(252)   '252 average number of trading days in a year

MsgBox "The annualised volatility for your selected range is: " & StkVol & ""

MsgBox "Would you like to use the annualised volatility to calculate the sharpe ratio of the selected range?", vbYesNo
    If MsgResult = vbNo Then Exit Function