How to format text in a mailto:

Could someone please help with a mailto action
I am trying something like this, I want the text in $the_message to be
formatted. The results I get is unformatted. line 1 line 2 line 3 line 4
.... line etc.

<?
<a href='mailto:email@xxxxxxx&subject=$subject&body=$the_message'>mail me</a>
?>


<? $the_message=
" line 1\n"
.." line 2\n"
.." line 3\n"
.." line 4\n"
.." line 5\n"
.." line 6\n"
.." line 7\n"
.." line etc.\n";
?>
.