Drupal 7.x

I am trying to generate a pop-up page to request user for more input from a page generated by views module. I already had my code to generate the button by the following code

About 6 weeks into Drupal, finally gettin the hang of things. The whole point of going Drupal was the Agreservations module. I created my site hierarchy and links and 2 days ago thought I should begin configuring Agreservations. I noticed some modules needed installed and some also enabled. As I am new to this I clicked the check box for all the Modules I could think needed enabled. I was presented with the error I will post below and that the Views module was needed enabled first before others could. So I went back to modules, selected only Views and ever since I get this:

Error
The website encountered an unexpected error. Please try again later.
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, cgiadmin@yourhostingaccount.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Hello, I have upgraded to 7 and have been backing up the file system in the WWW folder and the database. I did this backup after going to 6.22 (accor. to instructions), then after going to 7, then after installing a group of modules, etc. However, somewhere along the line the database update.php page now only says "No Pending Updates", i.e. it doesn't show any errors, but also doesn't seem to do any work when update.php is run. Also, somewhere along the line the links in the admin toolbar (other than the home button in the top left and the user name in the top right) have disappeared.

I need a PHP snippet that turns a current node body into a 50 character teaser. I have 0 education in PHP code so if anyone could help me write this (what seems to be) basic code snippet, I would very much appreciate it!

Hi,
I am new in Drupal, I never try it until 2 days ago. I found that this system is very powerful, but not easy figure it out how it works.

I wonder how dp sorting a list of nodes under taxonomy in the front-end. Previously, I am Wordpress user, its category listing is very easy to understand. But not like this, I don't even sure if the taxonomy is behave like category in wordpress. Maybe I should change my mindset in order to understand dp.

By the way, I also don't sure that I am in the right forum to ask. If I am in the wrong place, please tell me where to go.

How scalable is the multisite module Domain Access to the installation of 100's possibly 1000's of domains? I read in other forums from several years ago that a multisite installation of more than 50 domains became problematic in Domain Access - is this still the case? Or, with the advent of Drupal 7 is Domain Access now capable of handling 100's of domains?