Why am I getting this error?

[blakemckenna]

I am very new to using Javascript. I just wrote a function and I'm trying to call it when my page loads and I'm getting this (see screen shot). Below is the actual function code.

            function FormatInsuranceGrid() {
                var grid = igtbl_getGridById('UG_MarketStatis');

                if (grid.Rows.length > 0) {
                    for (var i = 0; i < grid.Rows.length; i++) {
                        if (grid.Rows.getRow(i).getCellFromKey("Market_Data_Amt").getValue() != null) {
                            var marketData = grid.Rows.getRow(i).getCellFromKey("Market_Data_Amt").getValue();
                            var iID = grid.Rows.getRow(i).getCellFromKey("ID").getValue();

                            if (iID == 1) {
                                grid.Rows.getRow(i).getCellFromKey("Market_Data_Amt").setValue(parseFloat(FormatPercentNew(marketData, 2)));
                            }
                            else {
                                grid.Rows.getRow(i).getCellFromKey("Market_Data_Amt").setValue(parseFloat(FormatCurrencyNew(marketData, 2)));
                            }
                        }
                    }
                }
            }