src/Easy/Element/ColumnListbox.php
public function renderLabel()
    {
        if ($this->sortable == "Y")
        {
            $rule = $this->objectName;

            $function = $this->formName . ".SortRecord($rule,$this->sortFlag)";
            if($this->sortFlag == "ASC" || $this->sortFlag == "DESC"){
            	$class=" class=\"current\" ";
            }else{
            	$class=" class=\"normal\" ";
            }
            if ($this->sortFlag == "ASC")
            	$span_class = " class=\"sort_up\" ";
            else if ($this->sortFlag == "DESC")
                $span_class = " class=\"sort_down\" ";
            $sHTML = "<a href=javascript:Openbizx.CallFunction('" . $function . "') $class ><span $span_class >" . $this->label ."</span>";            
            $sHTML .= "</a>";
        }
        else
        {
            $sHTML = $this->label;
        }
        return $sHTML;
    }
public function renderLabel()
    {
        if ($this->sortable == "Y")
        {
            $rule = $this->objectName;

            $function = $this->formName . ".SortRecord($rule,$this->sortFlag)";
            if($this->sortFlag == "ASC" || $this->sortFlag == "DESC"){
            	$class=" class=\"current\" ";
            }else{
            	$class=" class=\"normal\" ";
            }
            if ($this->sortFlag == "ASC")
            	$span_class = " class=\"sort_up\" ";
            else if ($this->sortFlag == "DESC")
                $span_class = " class=\"sort_down\" ";
            $sHTML = "<a href=javascript:Openbizx.CallFunction('" . $function . "') $class ><span $span_class >" . $this->label ."</span>";            
            $sHTML .= "</a>";
        }
        else
        {
            $sHTML = $this->label;
        }
        return $sHTML;
    }
When render table, it return the table header; when render array, it return the display name

@return string HTML text