In case of the test which you need to display has no blanks or other white-space you can’t use the CSS style described here and here.
I would recommend you to use another CSS style:
<style type="text/css">
.ui-jqgrid tr.jqgrow td {
word-wrap: break-word; /* IE 5.5+ and CSS3 */
white-space: pre-wrap; /* CSS3 */
white-space: -moz-pre-wrap; /* Mozilla, since 1999 */
white-space: -pre-wrap; /* Opera 4-6 */
white-space: -o-pre-wrap; /* Opera 7 */
overflow: hidden;
height: auto;
vertical-align: middle;
padding-top: 3px;
padding-bottom: 3px
}
</style>
How you can see from the demo the text “testtesttesttesttesttesttesttesttest” will be displayed as the following: