I am getting some long list of error . Can anyone suggest me where i am wrong with group layout
layout.setHorizontalGroup(
layout.createSequentialGroup()
.addComponent(new JLabel("Enter Book Name"))
.addComponent(new JTextField("TextField", 20))
);
ERROR
Exception in thread "main" java.lang.IllegalStateException: javax.swing.JTextField[,0,0,0x0,invalid,layout=javax.swing.plaf.basic.BasicTextUI$UpdateHandler,alignmentX=0.0,alignmentY=0.0,border=javax.swing.plaf.BorderUIResource$CompoundBorderUIResource@3d0bbf9e,flags=296,maximumSize=,minimumSize=,preferredSize=,caretColor=sun.swing.PrintColorUIResource[r=51,g=51,b=51],disabledTextColor=javax.swing.plaf.ColorUIResource[r=184,g=207,b=229],editable=true,margin=javax.swing.plaf.InsetsUIResource[top=0,left=0,bottom=0,right=0],selectedTextColor=sun.swing.PrintColorUIResource[r=51,g=51,b=51],selectionColor=javax.swing.plaf.ColorUIResource[r=184,g=207,b=229],columns=20,columnWidth=0,command=,horizontalAlignment=LEADING] is not attached to a vertical group
at javax.swing.GroupLayout.checkComponents(Unknown Source)
at javax.swing.GroupLayout.prepare(Unknown Source)