$("table").on('click', '.tr_condition', CloneCondition);

​

var addIDs = ['tabl','col','oper','val'];

var cloneCount = 0;

​

function CloneCondition(){

    cloneCount++;

    $(this).closest('.tr_cond')

        .clone()

        .insertAfter(".tr_cond:last");

    // after clone is done let's go for the last (new) one

  $('.tr_cond:last td').not(':last').each(function(i){

       $(this).attr('id', addIDs[i] +'Cond'+ cloneCount);

    });

}