Meta box make image width 100%

Hi please can you let me know how I should edit this so it selects

Slider width: 100% width
Slider height: Auto height

<tr id=”L3″>
<th scope=”row”><label><?php _e(‘Slider Width’, URIS_TD); ?></label></th>
<td>
<?php if(!isset($WRIS_L3_Slider_Width)) $WRIS_L3_Slider_Width = 1000; ?>
<?php if(!isset($WRIS_L3_Width)) $WRIS_L3_Width = “custom”; ?>
<input type=”radio” name=”wl-l3-width” id=”wl-l3-width” value=”100%” <?php if($WRIS_L3_Width == “100%” ) { echo “checked”; } ?>> <?php _e(‘100% Width’, URIS_TD); ?>   
<input type=”radio” name=”wl-l3-width” id=”wl-l3-width” value=”fullWidth” <?php if($WRIS_L3_Width == “fullWidth” ) { echo “checked”; } ?>> <?php _e(‘Full Width’, URIS_TD); ?>   
<input type=”radio” name=”wl-l3-width” id=”wl-l3-width” value=”custom” <?php if($WRIS_L3_Width == “custom” ) { echo “checked”; } ?>> <?php _e(‘Custom’, URIS_TD); ?>
<input type=”text” name=”wl-l3-slider-width” id=”wl-l3-slider-width” value=”<?php echo $WRIS_L3_Slider_Width; ?>”>
<p class=”description”>
<?php _e(‘Enter your desired width for slider. Default width is 1000px’, URIS_TD); ?>.
<?php _e(‘Preview’, URIS_TD); ?>
</p>
</td>
</tr>

<tr id=”L3″>
<th scope=”row”><label><?php _e(‘Slider Height’, URIS_TD); ?></label></th>
<td>
<?php if(!isset($WRIS_L3_Slider_Height)) $WRIS_L3_Slider_Height = 500; ?>
<?php if(!isset($WRIS_L3_Height)) $WRIS_L3_Height = “custom”; ?>
<input type=”radio” name=”wl-l3-height” id=”wl-l3-height” value=”auto” <?php if($WRIS_L3_Height == “auto” ) { echo “checked”; } ?>> <?php _e(‘Auto Height’, URIS_TD); ?>   
<input type=”radio” name=”wl-l3-height” id=”wl-l3-height” value=”custom” <?php if($WRIS_L3_Height == “custom” ) { echo “checked”; } ?>> <?php _e(‘Custom’, URIS_TD); ?>
<input type=”text” name=”wl-l3-slider-height” id=”wl-l3-slider-height” value=”<?php echo $WRIS_L3_Slider_Height; ?>”>
<p class=”description”>
<?php _e(‘Enter your desired height for slider. Default height is 500px’, URIS_TD); ?>.
<?php _e(‘Preview’, URIS_TD); ?>
</p>
</td>
</tr>

Thanks
James