Validating DataList. when datalist count is zero

here i am uploading company products, after that i am saving all products into databas.

i want give the RequiredFieldValidator to DataList, when DataList is empty.

and also display in ValidationSummary

// if (DataListCProductsImgs.Items.Count=0 )

// RequiredFieldValidator Fire ---"Upload one product"

i want to do in javascript or jquer ...

i tryed..

custom validator , But ControlToValidate= ?

function gettotalRows(sender, arguments)

{

var totalRowCount = $("[id*=DataListCompanyImgs] tr").length;

if(totalRowCount>0)

{

arguments.IsValue = true;

}

is there any another method.. to validate clientside.

Help me ..

Thanks