KoolGrid supports row selecting. Simply set $AllowSelecting property to true, you can enable this feature.
<?php
require $KoolControlsFolder."/KoolAjax/koolajax.php";
$koolajax->scriptFolder = $KoolControlsFolder."/KoolAjax";
require $KoolControlsFolder."/KoolGrid/koolgrid.php";
require $KoolControlsFolder."/KoolGrid/ext/datasources/MySQLiDataSource.php";
$ds = new MySQLiDataSource($db_con);//This $db_con link has been created inside KoolPHPSuite/Resources/runexample.php
$ds->SelectCommand = "select customerNumber,customerName,phone,city from customers";
$grid = new KoolGrid("grid");
$grid->scriptFolder = $KoolControlsFolder."/KoolGrid";
$grid->styleFolder="default";
$grid->MasterTable->DataSource = $ds;
$grid->MasterTable->DataKeyNames = "customerNumber"; // Need to set to get selection.
$grid->Width = "655px";
$grid->AllowSelecting = true;// Allow row selecting
$grid->AjaxEnabled = true;
$grid->AutoGenerateColumns = true;
$grid->MasterTable->Pager = new GridPrevNextAndNumericPager();
$grid->Process();
//Get selected keys after grid processing
$selected_keys = $grid->GetInstanceMasterTable()->SelectedKeys;
?>
<form id="form1" method="post">
<?php echo $koolajax->Render();?>
<?php echo $grid->Render();?>
<div style="padding-top:10px;">
<input type="submit" value = "Submit" />
</div>
<div style="padding-top:10px;">
<?php
if (sizeof($selected_keys)>0)
{
echo "You select row with <b>customerNumber = ".$selected_keys[0]["customerNumber"]."</b>";
}
?>
</div>
</form>