js实现textarea提示框验证

<textarea class="input_s1" name="cmInqriry.inquiryContent" cols="26" rows="4" id="cmInqriry.inquiryContent" title="<s:text name="common.alst.beizhu4.title.product.note"/>" onclick="test(this)" onblur="onBlure(this)" ><s:text name="common.alst.beizhu4.title.product.note"/></textarea><font color="red">*</font>function test(obj){if( obj.value=="在此写清其他说明或者货品数量，增票详情等" ||obj.value=="This include full instructions or quantity of goods and VAT details" ){obj.innerHTML='';document.getElementById("cmInqriry.inquiryContent").className="input_s2";}else{}}function onBlure(obj){if(obj.value!=''){if(obj.value!="在此写清其他说明或者货品数量，增票详情等" ||obj.value!="This include full instructions or quantity of goods and VAT details" ){document.getElementById("cmInqriry.inquiryContent").className="input_s2";}}else{var bLang = dojo.byId("bLang").value;if(bLang==1){document.getElementById("cmInqriry.inquiryContent").className="input_s1";obj.innerHTML='在此写清其他说明或者货品数量，增票详情等';}else{document.getElementById("cmInqriry.inquiryContent").className="input_s1";obj.innerHTML='This include full instructions or quantity of goods and VAT details';}}}