You can grab the values from the global $_REQUEST array or $_POST array. The selected values are avaialble in the variable which has the same name as the form tag. e.g. the selected value for subject...

I couldn't see any wrong in your code.

After the form is posted all the form variables are available in the second page in the global array $_REQUEST[]. So when you want to keep the form variables in the first page then do this:

<input...

What google is saying?

Because you have set the primary key to be auto incremented so you don't need to pass anything here.

Pass the result resource you get after executing the query in mysql_num_rows() and it'll give the total number of rwos fetched

Or if you want to follow CSS to desig the grid which very popular then you can choose the CSS you want from this tutorial also-...

Very simple, you can use either
<a href="..." target="_BLANK">...</a>
or use javascript function window.open() to open a new window having the link you specified