html - Frozen table header inside scrollable div -

I have three divs, a table in the header, middle, and footer central div (grapevoo) that is almost always with the outer div That's why I have made this div scrabble vertical. The question is: How can I create table headers that will appear after scrolling down the div? I could have used this header with a separate division or table and could decide it, but the width of columns is not always the same in the table - so I do not know how to maintain the width of the column in the header. any clue?

Here is a basic solution using Javascript:

  function Position (table) {table.rows [0] .style.position = "full"; Table.rows [0] .style.top = "0px"; Table.style.marginTop = table.rows [0] .clientHeight / 1.2; Var widths = Array (); For (var i = 0; i.low; table. [[0] .cells.length; i ++) {widths [i] = max (tables. Rosh [0]. Seals [i] .kentwuthth, Table .ro [1] .cells [i] .clientWidth); } For {var row = 0; line & lt; table.rows.length; row ++} {for (var col = 0; col & lt; widths.length; col ++) {table.rows [row] . Cells [col] Style.width = widths [col] + "px"; }}} Maximum function (num1, num2) {return (num1 & num; num2)? Num1: num2; }