JQGrid Horizontal srollbar not working - jqgrid

Question

Experts,
I need horizontal scrollbar in my JQgrid. The scrollbar is visible but it does not work as the columns are getting wrapped. I do not want wrapping and allow user to scroll horizontally. I tried everything found on google but in vain. Going forward the number of columns would increase. Please help.
$("#test1").jqGrid({
url: hostPath + '/test/test',
postData: {
modelDataRequest: window.ModelPart
},
datatype: 'json',
mtype: 'Post',
height: 'auto',
colNames: ['Col1', 'Col2','col3','col4','col5', 'col6', 'col7','col8', 'col9', 'col10', 'col11', 'col12'],
colModel: [
{name: 'col1', index: 'col1', width: '150px', search: true, align: 'left'},
{name: 'col2', index: 'col2', width: '150px', search: true, align: 'left'},
{name: 'col3', index: 'col3', width: '150px', search: true, align: 'left'},
{name: 'col4', index: 'col4', width: '150px', search: true, align: 'left'},
{name: 'col5', index: 'col5', width: '150px', search: true, align: 'left'},
{name: 'col6', index: 'col6', width: '150px', search: true, align: 'left'},
{name: 'col7', index: 'col7', width: '150px', search: true, align: 'left'},
{name: 'col8', index: 'col8', width: '150px', search: true, align: 'left'},
{name: 'col9', index: 'col9', width: '150px', search: true, align: 'left'},
{name: 'col10', index: 'col10', width: '150px', search: true, align: 'left'},
{name: 'col11', index: 'col11', width: '150px', search: true, align: 'left'},
{name: 'col12', index: 'col12', width: '150px', search: true, align: 'left'},
],
gridview: true,
loadOnce: true,
sortable: true,
shrinkToFit: false,
//search: true,
pager: '#Pager',
jsonReader: { cell: "" },
rowNum: 50,
rowList: [10, 20, 50, 100, 500, 1000],
viewrecords: true,
emptyrecords: 'No record(s) to display',
caption: "Search Results",
altRows: true,
altclass: 'jqGridAltRow',
loadComplete: function () {
if ($(this).getGridParam("records") == 0) {
$(this).parents('div.ui-jqgrid-div').css("max-height", "0px");
$(this).html("<div style='padding:6px;background:#D8D8D8'>No records found</div>");
}
else {
$(this).parents('div.ui-jqgrid-div').css("max-height", "450px");
}
$(this).parents('div.ui-jqgrid-div').css("max-width", "100%");
},
gridComplete: function () {
$('#recordsCount').text($('#test1').getGridParam('records'));
},
},
{
closeOnEscape: true, closeAfterSearch: true, ignoreCase: true, multipleSearch: true, multipleGroup: true, showQuery: true,
sopt: ['cn', 'eq'],
defaultSearch: 'cn'
})