Click "Show popup" 5 times. the button no response.

[zhengying]

OS : mac os 10.8.4

runtime error here:

goroutine 90 [running]:
net/http.func·009()
/usr/local/go/src/pkg/net/http/server.go:1093 +0xae
runtime.panic(0x42316a0, 0x450af59)
/usr/local/go/src/pkg/runtime/panic.c:248 +0x106
github.com/thingalon/goui.handleAjaxRequest(0x467d7e0, 0xc2102d9500, 0xc210255680)
/Users/zhengying/GOPROJ/src/github.com/thingalon/goui/goui.go:187 +0x457
net/http.HandlerFunc.ServeHTTP(0x42f0a90, 0x467d7e0, 0xc2102d9500, 0xc210255680)
/usr/local/go/src/pkg/net/http/server.go:1220 +0x40
net/http.(_ServeMux).ServeHTTP(0xc21001e780, 0x467d7e0, 0xc2102d9500, 0xc210255680)
/usr/local/go/src/pkg/net/http/server.go:1496 +0x163
net/http.serverHandler.ServeHTTP(0xc21001f460, 0x467d7e0, 0xc2102d9500, 0xc210255680)
/usr/local/go/src/pkg/net/http/server.go:1597 +0x16e
net/http.(_conn).serve(0xc210058800)
/usr/local/go/src/pkg/net/http/server.go:1167 +0x7b7
created by net/http.(*Server).Serve
/usr/local/go/src/pkg/net/http/server.go:1644 +0x28b
2014/09/04 15:45:37 http: panic serving 127.0.0.1:52026: runtime error: invalid memory address or nil pointer dereference