[AndrewGSW]

Would somebody post the actual complete code to show me?

Homework.. ?!

JavasScript doesn't use 'Dim' - that's Visual Basic - it uses 'var'.

The following demonstrates a looping structure:

function createRows(noOfRows) {
    var x;
    for (x=0; x < noOfRows; x++ ) {
        // obtain or calculate principal, period, etc..
        // add a row to the table, 
        // inserting the principal, etc., into the correct cells as you go
        // (you already have some code that inserts a row)
    }
}