Data grid with check box question

HI,

im using the following code for using data grid and I have two question

1.when I click on the checkbox its not selected on the first click ,how can I change it that when the user

click just one time the check box was select

2.when you select the check box all the line was marked with blue ,how can I omit the blue mark?

<DataGridRowHeaderWidth="0"ItemsSource="{Binding Items}"AutoGenerateColumns="False"><DataGrid.Columns><DataGridCheckBoxColumnBinding="{Binding Column1, UpdateSourceTrigger=PropertyChanged}"Header="1"/><DataGridTextColumnBinding="{Binding Column2}"Header="2"/><DataGridTextColumnBinding="{Binding Column3}"Header="3"/><DataGridTextColumnBinding="{Binding Column4}"Header="4"/><DataGridTextColumnBinding="{Binding Column5}"Header="5"/></DataGrid.Columns><DataGrid.ItemContainerStyle><StyleTargetType="DataGridRow"><Style.Triggers><DataTriggerBinding="{Binding Column1}"Value="True"><SetterProperty="Background"Value="Gray"/></DataTrigger></Style.Triggers></Style></DataGrid.ItemContainerStyle></DataGrid>