function IsDigit(cCheck){      
	return (('0'<=cCheck) && (cCheck<='9'));      
}      
      
function IsAlpha(cCheck){      
	return ((('a'<=cCheck) && (cCheck<='z')) || (('A'<=cCheck) && (cCheck<='Z')));     
}
function IsValidLen(str,minlen,maxlen){
	return ((str.length>=minlen) && (str.length<=maxlen));
} 
function IsValidStr(str){//是否是英文字母开头
	return (IsAlpha(str.charAt(0)));
}
function JRTrim(sString)
{ 
	var sStr,i,sResult = "",sTemp = "" ;
	
	if (sString.length == 0) { return "";} // 参数sString是空串
	else{
		sStr = sString.split("");
		for (i = sStr.length - 1 ; i >= 0 ; i --)  // 将字符串进行倒序
		{ 
			sResult = sResult + sStr[i]; 
		}
		sTemp = JLTrim(sResult) ; // 进行字符串前空格截除
		
		if (sTemp == "") { return "" ; }
		
		sStr = sTemp.split("");
		sResult = "" ;
		for (i = sStr.length - 1 ; i >= 0 ; i--) // 将经处理后的字符串再进行倒序
		{
			sResult = sResult + sStr[i];
		}
		return sResult ;
	}
}
 
function JTrim(sString)
{
	var strTmp ;
	strTmp = JRTrim(JLTrim(sString)) ;
	return strTmp ;
}