Update subscriptions.php

I found answer in topic 
http://stackoverflow.com/questions/2984311/delete-default-value-of-an-input-text-on-click 
from (Jani).
With this modyfication user can click on input field and if it has default value it will be cleared. 
Handels click out element (inserted text remains).

Just insert this script (after line 648):
'script>
function onBlur(el) {if (el.value == '') { el.value = el.defaultValue; }}
function onFocus(el) {if (el.value == el.defaultValue) {el.value = '';}}
</script'

And change line (oryginal) 649 from:
'input type="email" name="email" value="<?php echo esc_attr( $subscribe_email ); ?>" id="<?php echo esc_attr( $subscribe_field_id ); ?>" placeholder="<?php echo esc_attr( $subscribe_placeholder ); ?>" /'

to:
'input type="email" name="email" value="<?php echo esc_attr( $subscribe_email ); ?>" id="<?php echo esc_attr( $subscribe_field_id ); ?>" placeholder="<?php echo esc_attr( $subscribe_placeholder ); ?>"onblur="onBlur(this)" onfocus="onFocus(this)" /'