var col = ["fName","fCOde","fID"];
var defCols = {};
for(var i =0;i<col.length;i++){
var key = col[i];
var value = {type:'String',label:key};
defCols[key] = value;
}
var data = new Data(this,{
xid : 'mainData',
defCols : defCols ,
idColumn : 'fID'
});