Onfocus: How to stop it prompting IE security box?

I have this on an html:

   <input type="text" name="username" size="10" alt="Username" value="Username"
    onfocus="if(this.value=='Username') this.value='';" />

But this prompts an irritating IE security box on browser.

It there anything I can do to get rid of that IE box? Or any other option to use to the same effec开发者_如何转开发t?

Thanks!

Maria

Are you running the page from your computer? (i.e. double clicked on the .html file?) Usually Internet Explorer does this for local files to prevent attacks. Open this and see if the yellow bar comes up. http://jsfiddle.net/25xBW