I have an input text:
<input name="Email" type="text" id="Email" value="email@abc.example" />
I want to put a default value like "What’s your programming question? be specific." in Stack Overflow, and when the user click on it the default value disapear.
For future reference, I have to include the HTML5 way to do this.
If you have a HTML5 doctype and a HTML5-compliant browser, this will work. However, many browsers do not currently support this, so at least Internet Explorer users will not be able to see your placeholder. However, see JQuery HTML5 placeholder fix « Kamikazemusic.com for a solution. Using that, you’ll be very modern and standards-compliant, while also providing the functionality to most users.
Also, the provided link is a well-tested and well-developed solution, which should work out of the box.