I'm trying to create a popup using ClientFormatFunc but I need to pass string parameters and I'm having a problem with the format of the params. I can do this with integer parameters but I'm getting errors with strings. I also need to send multiple parameters and wondered how that should be formatted. Here's the ClientFormatFunc:

function openDetailsPopupFunc(compliance) {
    return '<button type="button" class="awe-btn o-pad" onclick="awe.open(\'openDetailsPopup\', {params:{ driverId: ' 
+ compliance.DriverId + ', startDate: ' + compliance.ReportStartDate + ', endDate: ' + compliance.ReportEndDate + ' }}, event)">View</button>';
}

When I look at the elements that are being rendered in the browser, I can see that the proper values are being added to params, but I'm assuming that because they're string values and not enclosed in double quotes it's having problems.