Using this line i set the value of label
Ext.getCmp('number_id').setText('<b><font size="2">'+3438+'</font></b>',false);
and on the UI i found it like
clearly 8 is not in same line.
Please help with reason.
Added the face and working now :
Ext.getCmp('number_id').setText('<b><font face="arial" size="2">'+3438+'</font></b>',false);