<html> <head> <meta charset="utf-8"/> <script src="jquery.js"></script> </head> <body> <script> function check1(){ $("#text").text("猫"); } function check2(){ $("#text").text("犬"); } </script> <textarea id="text"></textarea> <input type="button" onclick="check1();" value="a"> <input type="button" onclick="check2();" value="b"> </body> </html>