Creating a huge html form with lot of sections in one page

Hi! All

I am currently working on a project for a data entry product, where I have one html form with more than 100 Html form elements in one page.

First I have Main section where it has 28 html form elements(textfield, dropdown, text area and …). Then I have Seven datagrid sections where the user can enter the data(inline edit within the data gird) to enter data. http://trirand.com/blog/jqgrid/jqgrid.html

I have two options,1) Main section plus all the 7 datagrid in accordions 2) Main section plus all the 7 datagrid in tabs.

I cannot have a step down approach (step1>step2>step3 and so on…) because the client needs in one page. And its not necessary he wants to enter all the datagrid they are optional. the user will enter Main section + two datagrid or Main section + four datagrid.

I am really struggling because the accordions and tabs have problems while implementing the error validation or showing errors.

Please let me know if someone has come up with this kind of data entry product which is the best way to handle the data entry without accordions and tabs

Regards
Deepak

Only accordions or tabs? What about simple hide-show (if the user wants to fill in a data grid, they click open a link or answer a form control to show that)?