Validating Currency and Number upto 4 decimals

Question :

I would like to validate whether a string satisfy the following currency format with maximum 4 decimal places and could allow ',' regardless of culture.
Eg:
2,000,000(valid)
200000.0000(valid)
200 (valid)
200.00000(invalid)

How could it be done?

Solution :

I have tried this on a web application :

design page :

<asp:TextBox ID="txtNumber" runat="server"></asp:TextBox>
    <asp:Button ID="btnCheck" runat="server" Text="check" onclick="btnCheck_Click" />
    <asp:Label ID="lblResult" runat="server"></asp:Label>

code page :

protected void btnCheck_Click(object sender, EventArgs e)

{

string NumberEntered = txtNumber.Text;

if (NumberEntered.Contains('.'))

{

string[] newNumber = NumberEntered.Split('.');

if (newNumber.Length == 2)

{

string noOfZeros = newNumber[1];

if (noOfZeros.Length <= 4)

{

lblResult.Text = "Number is accepted";

}

else

{

lblResult.Text = "Number is not accepted";

}

}

}

else

{

lblResult.Text = "Number is accepted";

}

}