javascript - Extjs4: TreeStore with method POST -

i have ext.tree.panel , define in have store. want able update store via ajax along post params.

here tree definition:

var mytree = ext.create('ext.tree.panel',{     rootvisible:false,     store:ext.create('ext.data.treestore', {                 root:{             id:'rootnode',             nodetype:'async'                  },         proxy:{             method:'post',             type:'ajax',                         url:'myurl'         }     })     }); 

and try , reload store follows:

mytree.store.load({params:{search_string='value'}}) 

but store attempts reload params get parameters.

some appreciated. extjs 4 docs arent great @ moment (in opinion)

there actionmethods parameter in proxy specify method of requests: http://dev.sencha.com/deploy/ext-4.0.0/docs/api/ext.data.proxy.ajax.html

proxy:{     actionmethods: {         create: 'post',         destroy: 'delete',         read: 'post',         update: 'post'     },     type:'ajax',                 url:'myurl' }