AJAX的基本段落

var objXMLHttp = false; function AjaxTest() { try { objXMLHttp = new ActiveXObject("Microsoft.XMLHTTP"); } catch (e) { try { objXMLHttp = new ActiveXObject("Msxml2.XMLHTTP"); } catch (e2) { objXMLHttp = false; } } if (!objXMLHttp && typeof XMLHttpRequest != 'undefined') { objXMLHttp = new XMLHttpRequest(); } var objVal = null; if(document.getElementById("txtVal")!=null) { objVal = document.getElementById("txtVal"); } if(objVal!=null) { var url = "AjaxEncodeTest.aspx?Val=" + objVal.value; //请求的页面 objXMLHttp.open("Get", url, true); //编码设置 objXMLHttp.setRequestHeader("Content-Type","text/xml; charset=utf-8"); objXMLHttp.onreadystatechange = callBack; objXMLHttp.send(null); } } function callBack() { var objVal; if(document.getElementById("Val")!=null) { objVal = document.getElementById("Val"); } if(objVal!=null) { if(objXMLHttp.readyState == 1) { objVal.value ="加载中...."; } if (objXMLHttp.readyState == 4) { //显示返回的结果 var sc = objXMLHttp.responseText; objVal.value = sc; document.getElementById("Val_DIV").innerHTML = sc; } } }