Display another list fields in popup and save within single form

Forms
11

Hello @harshp924,

You can calculate the total by the column. Please see this post for the code sample:

And you can use the below code to disable Add New Item button if the total is greater than or equal to 20:

fd.field('Total').$on('change', function(value){
    if(value >= 20) {
        fd.control('SPDataTable0').buttons[0].disabled = true;
    }
});