What sort of Error is this ?

well here is the part of my code

VB Code:

Private msngMouseX()    As Single
Private msngMouseY()    As Single
 
 
Private Sub xic_MouseMove( _
    Index As Integer, _
    Button As Integer, _
    Shift As Integer, _
    x As Single, _
    Y As Single _
)
    If (Button = vbLeftButton) Then
        xic(Index).Move (xic(Index).Left + x - msngMouseX(Index)), _
                           (xic(Index).Top + Y - msngMouseY(Index))
 
      Else
        msngMouseX(Index) = x
        msngMouseY(Index) = Y
 
    End If
End Sub

well it runs fine but at run time when i m moving instances of Xic in my workspace here and there .. after some time .. VB prompts as " run time error '9' subscript out of range " ..
and hightlights this line in yellow

msngMouseX(Index) = x

what should i do to get rid of this problem

Add a debug.print statement in the left button statement, to get the values of everything. It should be easy to see which numbers are wrong.

no improvement added "debug.pring" like this

VB Code:

Private Sub xic_MouseMove( _
    Index As Integer, _
    Button As Integer, _
    Shift As Integer, _
    x As Single, _
    Y As Single _
)
    If (Button = vbLeftButton) Then
        xic(Index).Move (xic(Index).Left + x - msngMouseX(Index)), _
                           (xic(Index).Top + Y - msngMouseY(Index))
Debug.Print
      Else
        msngMouseX(Index) = x
        msngMouseY(Index) = Y
 
    End If
End Sub

... same result ... it shows same error and after some ... u r gettin what i m trying to do i m jus dragging instance of Xic inside workspace from here and there .... what should i do

No, I meant something like this:

VB Code:

debug.pring xic(Index).Left & "  " & x & "  " & msngMouseX(Index))

so you could see the values of the variables. What is the last variable?
add another line for the Y variables.

or when the program stops click on Debug and then you can print the value of Index in the immediate window.

How have you dimensioned msngMouseX?