You can replace the space to dashes using wordpress sanitize_title_with_dashes
function Try below code.
<a href="http://twitter.com/home?status=<?php echo sanitize_title_with_dashes(get_the_title(get_the_ID())); ?>.<?php get_the_permalink(get_the_ID());?>" class="twitter">
I have used get_the_title()
and get_the_content()
functions because these both function return the context instead of echo them, and i think you are concatenating the string.
Hope this help .