Hi,

Within an e-commerce website, the cart summary page allows customers to

change the quantities of ordered items. Within this page I want to add the

following restrictions :

* Restrict the value e.g. > 0 and < 10 ?
* Stop negative values
* Stop non-numeric characters.

I've used the following code (asp.net 1.1, vb.net 2003) to restrict the

first two, which works fine :

  

intQuantity references a textbox that the customer can edit the quantity of

the item they have selected. However to stop non-numeric characters I

thought of using the "IsNumeric" function. What I want to say is if the

value inputted is non-numeric thenxxxx. So I used the following code :

which then results in an error :

Compilation Error
Description: An error occurred during the compilation of a resource

required to service this request. Please review the following specific

error details and modify your source code appropriately.

Compiler Error Message: BC30455: Argument not specified for parameter

'Expression' of 'Public Function IsNumeric(Expression As Object) As

Boolean'.

Source Error:



Line 205:
Line 206: Line 207: If (IsNumeric <> (txtQuantity.Text))

OR (intQuantity <=0 OR intQuantity >10) Then
Line 208: Line 209: 'Display message advising item

is low in stock


Any ideas on how I can overcome this ?

Thanks,

If Not IsNumeric(txtQuantity.Text) Then
                Throw New Exception("Only numbers are allowed for quantity.")
            End If

>< As rich pointed out, IsNumeric is a function hence you have to supply a value to it IsNumeric(Value); is numeric returns a bool value.

I, however, would not Throw an exception here, rather just handle it with a friendly message or something to that effect.

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Thanks both

In the end I changed tatics and used an regular expression validator to solve this issue - thanks again for your inputs....