how i find relief from this error the error is undefined index: host in C:\wamp\www\serp-tracker\get_serps.php on line 42 -

i'm getting output code server giving me error

notice: undefined index: host in "c:\wamp\www\serp-tracker\get_serps.php on line 42"

any body can me provide me solution error

<div class="form-group" <input class="form-control" type="text" placeholder="host" <?php if($_get["host"]!=""){ echo 'value="'.$_get["host"].'"';}else{ echo 'value="'.$myhost.'"'; }?> name="host"> </div> 

use empty() check if available. try -

if(!empty($_get["host"])) 

if($_get["host"]!="") generate error if host not present.