jQuery Grid Plugin - jqGrid

Hi people,

please help me,

i need to find last row, something like row count

i would like to check if the data exist in the grid

that's my first problem

second

when the row is selected i would like to populate text fields,

i know how to do that via an button-select row and click button, but how to do that without clickin a button,  just select row and populate fields

i was searchin forum but didn't find what i need,

thanks