php - Have option display blank then on submit keep value selected -

is possible have first item in dropdown list blank , selected default when choosing item in dropdown list , hitting submit, having value stay there.

here example

<form action="" method="post" /> <select name="whatever" id="whatever"> <?php $selected = isset($_post["whatever"]) && $_post["whatever"] == 'whatever'; ?> <option value="" hidden="true" selected="selected"></option> <option value=1 onclick"selected='selected'">all</option> </select>  <input type="submit" name="submit" value="update"/> </form> 

currently if hit submit change selected value blank.

u may use

<form action="" method="post" /> <select name="whatever" id="whatever"> <option value="">select value</option> <option value=1 <?php if($_post["whatever"]==1) echo "selected='selected'";?> >all</option> <option value=2 <?php if($_post["whatever"]==2) echo "selected='selected'";?> >value one</option> </select>  <input type="submit" name="submit" value="update"/> </form>