[Plugin: MailChimp Widget] Cannot Add Disappearing Form Text

So I’ve been playing around with MailChimp Widget and trying to set it up the way I’d like, but I’m having a problem hacking the PHP to add disappearing form text.

Adding the form text was no problem at all. It happily accepted my value argument. The arguments it won’t accept are these:

onfocus="if(this.value==this.defaultValue)this.value='';" onblur="if(this.value=='')this.value=this.defaultValue;"

Obviously I know that’s fine code, and it works properly in my searchform.php. When I tuck that into the input tag, I get the WSOD and an error to the effect of:

Parse error: syntax error, unexpected T_CONSTANT_ENCAPSED_STRING in /home1/[redacted]/public_html/[redacted]/wp-content/plugins/mailchimp-widget/lib/ns_widget_mailchimp.class.php on line 300

I’m a bit confused about why it won’t accept these additions, and I’d appreciate any help in terms of a solution or workaround! Thank you!