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';
				}
		}
	}