http://www.zabbix.com/documentation/1.8/api/screen/get
In example written:
{
"jsonrpc":"2.0",
"method":"Screen.get",
"params":{
"search":

{"name": "zabbix"}

,
"output": "extend"
},
"auth":"6f38cddc44cfbb6c1bd186f9a220b5a0",
"id":2
}
But in reality ""search":

{"name": "zabbix"}

" - doesnt work, but ""filter":

{"name": "zabbix"}

" - work.

Also "resourcetype" not defined in documentation.