動的にカンマは入るけど、カーソル位置の指定ができんから入力(編集)しにくい…
なんか、カーソル位置を指定することができるげなことを書いてるページはあるけど、できるんかいな?
<HTML> <head> <script type="text/javascript"> var lastVal = ""; function doFormatNum() { var curVal = document.getElementById("num").value; var val = curVal; while (val.indexOf(",") > -1) { val = val.replace(",", ""); } if ((curVal != "+") && (curVal != "-") && (curVal != ".") && (isNaN(val) == true)) { alert("数値じゃないです"); document.getElementById("num").value = lastVal; return; } var dec = val.length; if (val.indexOf(".") > -1) { dec = val.indexOf("."); } var newVal = ""; if (dec > 0) { for ( var i = dec ; i > 0 ; i-- ) { var num = val.substr(i - 1, 1); if ((i != dec) && (((dec - i) % 3) == 0) && (num != "-") && (num != "+")) { newVal = "," + newVal; } newVal = num + newVal; } if (val.indexOf(".") > -1) { newVal = newVal + val.substr(dec); } } else { newVal = val; } document.getElementById("num").value = newVal; lastVal = curVal; } </script> </head> <body> <input type="text" id="num" onkeyup="return doFormatNum();" size="50" /> </body> </HTML>