How to execute Javascript on TextInput change not using button clicked like in examples

<Panel ux:Name="opcolortop" Visibility="{Panel1Visibility}" Background="{op_color_top}" Width="100%" Height="20" Alignment="TopLeft" Margin="0,0,0,0">
				<Text Value="{op_IN}" FontSize="14" TextColor="#191919"  Alignment="Left" Margin="2,2,0,0"/>
				<TextInput ux:Name="op_IN_qty" Value="{op_IN_qty}" FontSize="14" TextColor="#191919" Background="#FFF" Width="30" Height="15" MaxLength="3" TextAlignment="Center" Margin="160,0,0,1" InputHint="Number"/>
				<Text ux:Name="op_IN_Total" Value="{op_I_N_Total}" FontSize="14" TextColor="#191919" Background="#F0F0F0" Width="60" Height="15" MaxLength="6" TextAlignment="Center" Margin="290,0,0,1">
					<Button Clicked="{op_IN_qty_calc_function}"/>

When I enter a number in the TextInput I would like the Total to update without having to click the button.

Got it working. Used ValueChanged on TextInput and works like a charm. Fuse rocks!!!