In one of the projects I'm working on, there was a requirement that numbers entered in a webform should be formatted to add thousands separator to them. So I came up with these couple of functions, one to allow only numbers to be entered in the textbox, another to add thousands separator to the entered number.
function FilterKeys(TextBox, e)
{
var TextBoxContent = TextBox.value;
var strCheck = '1234567890';
var whichCode = (window.Event) ? e.which : e.keyCode;
if (whichCode == 13 || whichCode == 37 || whichCode==39 || whichCode==9) return true; // Enter
key = String.fromCharCode(whichCode); // Get key value from key code
if (strCheck.indexOf(key) == -1)
// Not a valid key
e.returnValue = false;
}
function AddThousandsSeparator(TextBox, e)
{
var TextBoxContent = TextBox.value;
var temp="";
TextBoxContent=TextBoxContent.split(',').join('');
s=TextBoxContent.split('').reverse();
for(i=0;i<s.length;i++)
{
if((i)%3==0 && i!=0)
temp+=',';
temp+=s[i];
}
var formattedString=temp.split('').reverse().join('');
TextBox.value=formattedString;
return true
}
Using these 2 functions is pretty simple. Here's an example
<asp:TextBox id="TextBox1" runat="server" onkeypress="FilterKeys(this,event)" onkeyup="AddThousandsSeparator(this,event)"></asp:TextBox>