function varType(v){
 if ( typeof v=== "object" ){
 if (v=== null ) return 'null' ;
 if (v. constructor )
 return (v. constructor .toString()).match(/(?: )[/w/$]+/)[ 0 ];
 if ( typeof typeof2=== 'undefined' && window .execScript){
 window .execScript( 'Function vbsTypeName(o):vbsTypeName=TypeName(o):End Function' , 'vbscript' );
 window .execScript( 'function typeof2(o){return vbsTypeName(o)}' , 'jscript' );
 }
 if ( typeof typeof2!== 'undefined' ){
 return typeof2(v);
 }
 return "object" ;
 }
 return typeof v;
}
//對于普通js常量和js對象，各瀏覽器是基本一致的
alert (varType()); //undefined
alert (varType( 100 )); //number
alert (varType({})); //Object
alert (varType([])); //Array
alert (varType(/ /)); //RegExp
alert (varType( new Date ())); //Date
alert (varType( Date )); //function
alert (varType( Object )); //function
alert (varType( RegExp )); //function
//對于DOM對象，各瀏覽器可能會有不同值
alert (varType( window )); //IE:HTMLWindow2 FF:Window
alert (varType( document )); //IE:HTMLDocument FF:HTMLDocument
alert (varType( document .body)); //IE:HTMLBody FF:HTMLBodyElement
alert (varType( Option )); //IE:Object FF:function
alert (varType( Image )); //IE:Object FF:function
alert (varType( navigator )); //IE:DispHTMLNavigator FF:Navigator
//以下幾個只適用于IE，其他內核瀏覽器不支持
alert (varType( ActiveXObject )); //IE:function
alert (varType( Enumerator )); //IE:function
alert (varType( new ActiveXObject ( "Scripting.Dictionary" ))); //IE:Dictionary
alert (varType( new Enumerator ())); //IE:Enumerator