如何清空textarea 的值

<textarea id="resultComment" style="height:100px;width:380px;text-align:left;" class="easyui-textbox"  data-options="multiline:true,validType:['length[0,60]']" ></textarea>

<input type="button" onclick="clear()" value="清空" />

function clear() {
 	$('#resultComment').textbox("setValue","");
 	
 }