asp.net 2010 message

Question

&nbsp;<p>In a vb.net 2010 webform application, I am going to display a popup javascript alert message for the user when there are 2 records in the database for the current school year for each unique student. This popup message is displayed since the user needs to update the database using vendor software.</p><p>For the javacript alert message, I have the following questions:</p><p>1. At the top the alert message, it says 'Message from Web Page' since that is probably the default value. Is there a way that I can change this message to something I want? If so, how can I change the message?</p><p>2. I am wondering what if there maximum length that I can display in the error message? If so, what is the maximum length? </p><p>3. &nbsp;Can I extend the maximum size of the message and if so, can you show me how to extend the size of the error message?</p><p>4. Can I change the display icon to be an error instead of a warning? If so, how would I accomplish this goal?</p>