body onload="f.a.select();"?phpecho 'a:'.htmlspecialchars($a);echo 'bra1:';$a1 = eregi_replace('(^[_.][:alnum:]-]+@([[:alnum:]][[:alnum:]-]*.)+[[:alpha:]]{2,3}$)',' a href="mailto:1"1/a ', $a) ;echo htmlspecialchars($a1);echo "bra1:$a1";echo 'bra2:';$a2 = eregi_replace('([[:alnum:]]+://([[:alnum:]][[:alnum:]-]*.)+[[:alpha:]]{2,3}([#?/\][^#?/\][:space:]][^[:space:]]*)?)', 'a href="1" target="_blank"1/a', $a);echo htmlspecialchars($a2);echo "bra2:$a2";// eregi('^[_.][:alnum:]-]+@([[:alnum:]][[:alnum:]-]*.)+[[:alpha:]]{2,3}$',$a) or die("not a email");?form name="f"input name="a" value="?php echo $a; ?"input type="submit" /form/body(本文来源于图老师网站,更多请访问http://m.tulaoshi.com/webkaifa/)