input正则 限制输入正整数和一个小数点并且小数点后3位
oninput="value=value.replace(/[^\d^\.]+/g,'').replace('.','$#$').replace(/\./g,'').replace('$#$','.').replace(/^(\-)*(\d+)\.(\d\d\d).*$/,'$1$2.$3')"
oninput="value=value.replace(/[^\d^\.]+/g,'').replace('.','$#$').replace(/\./g,'').replace('$#$','.').replace(/^(\-)*(\d+)\.(\d\d\d).*$/,'$1$2.$3')"