jQuery Grid Plugin - jqGrid

Hello.  I have written several custom formatters for columns and they are working.  However, one custom formatter that is given me an issue.  If I do the following, then there are no syntax errors on the page when it loads and the alert message is displayed when I hover over a column cell for this column:

function FormatMenu(cellValue, options, rowObject) {   
        var cellHTML;
       var spanID = 'spanTicker' + options.rowId;

      cellHTML = "<span id='" + spanID + "' onmouseover=ShowMenuNew('" + spanID + "'," + options.rowId + ") onmouseout=HideMenu('')>" + cellValue + " <img src='/applications/images/icons/action_arrow.gif' alt='' /></span>";

        return cellHTML;
    }

function ShowMenuNew(tickerSpan, row) {

 alert('ticker');

}

However, if I change the formatter function to pass in the rowObject or a JSON stringified version of the rowObject, I get a syntax error when the page loads:

function FormatMenu(cellValue, options, rowObject) {   
        var cellHTML;
       var spanID = 'spanTicker' + options.rowId;

      cellHTML = "<span id='" + spanID + "' onmouseover=ShowMenuNew('" + spanID + "'," + rowObject + ") onmouseout=HideMenu('')>" + cellValue + " <img src='/applications/images/icons/action_arrow.gif' alt='' /></span>";

        return cellHTML;
    }

Or this:

function FormatMenu(cellValue, options, rowObject) {   
        var cellHTML;
       var spanID = 'spanTicker' + options.rowId;

var rowString = JSON.stringify(rowObject);

cellHTML = "<span id='" + spanID + "' onmouseover=ShowMenuNew('" + spanID + "','" + rowString + "') onmouseout=HideMenu('')>" + cellValue + " <img src='/applications/images/icons/action_arrow.gif' alt='' /></span>";

        return cellHTML;
    }

Any particular reason for this?  I have tried several JS escape character but have not been able to get this to work.  Ideally, I would like to pass the rowObject or a JSON string of the rowObject from my formatter fucntion to the ShowMenuNew function.  Any thoughts?

Thank.