Some days back, I was faced with a small task. I had to make implement Javascript regular expression validation on a field. The requirement was simple; the field should have minimum three alphanumeric characters, including French characters. For you to have an idea, French characters include “accent aigu” and “accent grave” (you can read about French accents on wikipedia).

Okay so I had the requirement and I was all set. I created a RegularExpressionValidator element on my ASP.NET page and I added “[a-zA-Z0-9 ]” as ValidationExpression. The code looked like this:

<asp:TextBox ID="txtName" runat="server" />
<asp:RegularExpressionValidator ID="rexName" ControlToValidate="txtName"
  ValidationExpression="[a-zA-Z0-9 ][a-zA-Z0-9 ][a-zA-Z0-9 ]+"
  ErrorMessage="Please enter at least 3 alphanumeric characters." runat="server" />

This worked perfectly. It matched three alphanumeric characters or more. But the problem was it was not matching any of the French characters. After some Google searching and some code trial and errors, I came up with this “[a-zA-ZÀ-ÿ0-9 ]” as ValidationExpression. This worked like a charm. The new code was like this:

<asp:TextBox ID="txtName" runat="server" />
<asp:RegularExpressionValidator ID="rexName" ControlToValidate="txtName"
  ValidationExpression="[a-zA-ZÀ-ÿ0-9 ][a-zA-ZÀ-ÿ0-9 ][a-zA-ZÀ-ÿ0-9 ]+"
  ErrorMessage="Please enter at least 3 alphanumeric characters." runat="server" />

If you can’t see the logic, let me explain. The code now matches

• all characters from a to z (lowercase invariants)
• all characters from A to Z (uppercase invariants)
• all characters from À to ÿ (all accent characers including French accents in uppercase and lowercase)
• all digits from 0 to 9 (note that the requirement did not require the name to start with a non-digit)
• whitespaces (whitespace was not catered for in the requirement)

So there you go. You now have the regular expression validation for French characters. The beauty of regular expression validation is that it is hard to come up with, but it is very easy to implement.

Taking a look at the GMarker section in the Google Maps API, we realise that the constructor takes two arguments. GLatLng and GMarkerOptions. What we need is the GMarkerOptions, which specifies the map marker options. Taking a look at the GMarkerOptions, we see that the class has no constructor. It only has a list of properties. Among, the clickable property.

But how do we use those properties? A little bit of googling around gave me answer. It was found on the Official Google Maps API Blog. The solution is pretty simple. Just take a look on the code below and you will see what I mean.

var markerOptions = {
clickable: false
};
var marker = new GMarker(new GLatLng(37.4419,-122.1419), markerOptions);
map.addOverlay(marker);

As you can see, the code is very simple, but the documentation is not precise enough. Hope this helps you out. Just a note, map marker options should be separated by a comma.

To fix it, just change your code from:

document.body.onload = alert("Hello world");

to:

document.onload = alert("Hello world");

It appears that document.body.onload does not work on IE. Before, when I loaded the page, I used to get  the error dialog “A Runtime Error has occured” saying “Error: Not implemented“. On debug in Visual Studio, I’d get “htmlfile: Not implemented“. All these error messages are not very clear, but fortunately, the faulty line of code was highlighted.

I have not yet researched about the difference(s) between document.body.onload and document.onload in Firefox (or IE), but if you’re only using a small piece of javascript code, you should be alright with this fix.