need help checking for number in vb6

[icedece]

Hi guys i'm working on some code whereby the user inputs a distance and time they took spent running for days 1 to 6 and it works fine however I can't get it to display a message box if the user inputs letters instead of numbers. I've had a go at trying to do it and you can see my attempt in the code below and btw this is a module in case it helps.

Sub Main()
'Declaring variables used in the program
Dim distance As Integer
Dim time, totaldistance, totaltime, average As Single
 
'Loop that calls the following functions to display the message box 6 times and change the day
For i = 1 To 6
distance = Val(InputBox("Enter the km travelled on day" + Str$(i)))
If IsNumeric(distance) = False Then
MsgBox ("please enter a number")
End If
 
time = Val(InputBox("Enter the minutes taken on day" + Str$(i)))
If IsNumeric(time) = False Then
MsgBox ("please enter a number")
End If
 
totaldistance = totaldistance + dist
totaltime = totaltime + time
Next i
 
'Calculates and displays the total time, distance and kmph
MsgBox ("The total distance travelled over the week =" + Str$(totaldistance) + "kms")
MsgBox ("The total time taken running over the week =" + Str$(totaltime) + " minutes")
average = totaldistance / totaltime * 60
MsgBox ("Your average speed is =" + Str$(average) + " kmph")
End Sub