Question

how can you use insertBefore() when you don’t have the id, class or anything for the table but only the object?

var tbl_elm = $('the table');

$('<tr><td>txt</td></tr>').insertBefore(tbl_elm.eq(0));

somehow I need to tell the eq() that the index has to be found in a ‘TR’ tag

Answer 1

Try this:

var tbl_elm = $("TABLE");    
$('<tr><td>txt</td></tr>').insertBefore($("TR", tbl_elm).eq(0))

However, if the elements you are adding to the table will always be placed before the first row, the below code is better practice:

var tbl_elm = $("TABLE");
$('<tr><td>txt</td></tr>').prependTo(tbl_elm)