For example: When loading the first page,
code:
store.load({params:{start:0,limit:pageSize,Keyword:Ext.getCmp('input_name').getValue()}});
When click next Page (previous page) with parameters
doLoad: function (start){
record_start = start;
var o = {}, pn = this.paramNames;
o[pn.start] = start;
o[pn.limit] = this. pageSize;
var Keyword=Ext.getCmp('input_name').getValue(); //Get parameters
o['Keyword'] = Keyword;//Write parameters
this.store.load ({params:o});//Loading
}