[MANDATORY]:fills data values to the graph data structure and ensures faulty data is not input.
[MANDATORY]:fills data values to the graph data structure and ensures faulty data is not input. This function must be called once for every set of data. e.g.if( grLibInputGraphData(br,30,2004,0,"Yahoo") != grLibNone) return grLibInvData;
if( grLibInputGraphData(br,40,2004,1,"ATT") != grLibNone) return grLibInvData;
if( grLibInputGraphData(br,50,2001,2,"MSN") !=grLibNone) return grLibInvData;