自动检测数字替换非数字的正则表达式

!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
HTML>
 HEAD>
 TITLE> New Document /TITLE>
 META NAME="Generator" CONTENT="EditPlus">
 META NAME="Author" CONTENT="">
 META NAME="Keywords" CONTENT="">
 META NAME="Description" CONTENT="">
 /HEAD>
 BODY>
 input onkeyup='check(this)'/>
 /BODY>
 script>
function check(obj){	
	var sreg = /^-+.*/g;
	var zero = /^0[1-9]+\.*\d*/g;
	var val = obj.value;
	var plus = '';
	if(sreg.test(val)){
		val = val.replace(/-+/g,'');		
		plus = '-';		
	}
	val = val.replace(/\s+/g,'');	
	if(/^\.+.*$/.test(val)){
		val = '';
	}
	val = val.replace(/[^\d\.]/,'');
	val = val.replace(/(^\d+\.{1})(\d*).*/g,'$1$2');
	val = val.replace(/(^\d+\.\d{3})\d*/g,'$1');
	val = val.replace(/^[0]*(0{1})([1-9]*)(.*)/g,'$1$2$3');		
	if(zero.test(val)){
		val = val.replace(/0([1-9]+)(.*)$/,'$1$2');
	}
	
	obj.value = plus+val;
}
 /script>
/HTML>

function renumdou(str){
var regexp = /[^\d，,]]*/g;
newstr=str.replace(regexp,"");
return newstr
}