这个为什么执行到9就下不去了
<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=gkb"/> </head> <body> <script type="text/javascript"> var a =10; function x(){ a =a -1; document.write(a); setTimeout(x,1000) } setTimeout(x,1000); </script> </body> </html>