insert wont work

Try:

$sql2="insert into tbmod1  (id,q1,q2,q3,q4,q5,q6,q7,q8,q9,q10,q11,q12,user,section) values
(1, 'enter here1' ,'enter here2', 'enter here3', 'enter here4' ,'enter here5', 'enter here6','enter here7' ,'enter here8', 'enter here9','enter here10' ,'enter here11', 'enter here12','" . mysql_real_escape_string($myusername) ."','section1')";

$result2=mysql_query($sql2);

(Added single quotes around the user value, and added mysql_real_escape_string on the value itself.

Also confirm that your ID field is not an autonumber type field, trying to manually provide a value for ID if it is an autonumber field will break your insert.

For debugging I print the completed SQL statements to screen and then manually copy and paste them into phpmyadmin or SQL Server Management Studio (depending on what DB I'm working with) and then execute the statement and i can see any error messages straight away.

$sql2="insert into tbmod1  (id,q1,q2,q3,q4,q5,q6,q7,q8,q9,q10,q11,q12,user,section) values
(1, 'enter here1' ,'enter here2', 'enter here3', 'enter here4' ,'enter here5', 'enter here6','enter here7' ,'enter here8', 'enter here9','enter here10' ,'enter here11', 'enter here12','$myusername','section1')";

$result2=mysql_query($sql2);

OK i had a duplicate value. The id filed is listed as a Primary but I didnt create the thing as a Primary key and I cant remove primary key from this field

You can use ALTER statements to change the table definition, or you can use a GUI tool like HeidiSQL (free) to do it for you.

Just to confuse matters, you should be moving away from using mysql_* and switch to mysqli or PDO ;)