Thank you so much Hillary, your Answer Helped me a lot, I have one more question about this subject i write here and if have to make new question i will make a new question.
if i use instead of constant sections, repeated section i mean a child repeated section inside parent repeated section, and there is a drop down field on the parent with values "Step1", "Step2" and a Text Box it's name is "Reference No" on The parent Section, when i select a "Step1" or "Step2" from drop down and i Submit the form it sets the value of Reference No in parent section to for Example "REf-Step1-01" and also i have a Reference No in Child Repeated section when i Insert row and submit form it automatically sets the value in child repeated section to "REF-Step1-02" and also i have a step field like previous question in child repeated section that gets the value from the parent repeated section for example now is "Step1" depend on what is Select in parent repeated Section.