//Function to check if Number id Numeric
function IsNumeric(sText){
   var ValidChars = "0123456789.";
   var IsNumber=true;
   var Char;
 
   for (i = 0; i < sText.length && IsNumber == true; i++) 
      { 
      Char = sText.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
         {
         IsNumber = false;
         }
      }
   return IsNumber;
}

function ECheck(str) {
	var at="@";
	var dot=".";
	var lat=str.indexOf(at);
	var lstr=str.length;
	var ldot=str.indexOf(dot);
	if (str.indexOf(at)==-1){
	   return false;
	}
	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
	   return false;
	}
	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
	    return false;
	}
	if (str.indexOf(at,(lat+1))!=-1){
	    return false;
	}
	if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
	    return false;
	}
	if (str.indexOf(dot,(lat+2))==-1){
	    return false;
	}
	if (str.indexOf(" ")!=-1){
	    return false;
	}
	return true;					
}

function ccValidate(ccNumb) {  // v2.0
	var valid = "0123456789"  // Valid digits in a credit card number
	var len = ccNumb.length;  // The length of the submitted cc number
	var iCCN = parseInt(ccNumb);  // integer of ccNumb
	var sCCN = ccNumb.toString();  // string of ccNumb
	sCCN = sCCN.replace (/^\s+|\s+$/g,'');  // strip spaces
	var iTotal = 0;  // integer total set at zero
	var bNum = true;  // by default assume it is a number
	var bResult = false;  // by default assume it is NOT a valid cc
	var temp;  // temp variable for parsing string
	var calc;  // used for calculation of each digit

	// Determine if the ccNumb is in fact all numbers
	for (var j=0; j<len; j++) {
	  temp = "" + sCCN.substring(j, j+1);
	  if (valid.indexOf(temp) == "-1"){bNum = false;}
	}

	// if it is NOT a number, you can either alert to the fact, or just pass a failure
	if(!bNum){
	  /*alert("Not a Number");*/bResult = false;
	}

	// Determine if it is the proper length 
	if((len == 0)&&(bResult)){  // nothing, field is blank AND passed above # check
	  bResult = false;
	} else{  // ccNumb is a number and the proper length - let's see if it is a valid card number
	  if(len >= 15){  // 15 or 16 for Amex or V/MC
	    for(var i=len;i>0;i--){  // LOOP throught the digits of the card
	      calc = parseInt(iCCN) % 10;  // right most digit
	      calc = parseInt(calc);  // assure it is an integer
	      iTotal += calc;  // running total of the card number as we loop - Do Nothing to first digit
	      i--;  // decrement the count - move to the next digit in the card
	      iCCN = iCCN / 10;                               // subtracts right most digit from ccNumb
	      calc = parseInt(iCCN) % 10 ;    // NEXT right most digit
	      calc = calc *2;                                 // multiply the digit by two
	      // Instead of some screwy method of converting 16 to a string and then parsing 1 and 6 and then adding them to make 7,
	      // I use a simple switch statement to change the value of calc2 to 7 if 16 is the multiple.
	      switch(calc){
	        case 10: calc = 1; break;       //5*2=10 & 1+0 = 1
	        case 12: calc = 3; break;       //6*2=12 & 1+2 = 3
	        case 14: calc = 5; break;       //7*2=14 & 1+4 = 5
	        case 16: calc = 7; break;       //8*2=16 & 1+6 = 7
	        case 18: calc = 9; break;       //9*2=18 & 1+8 = 9
	        default: calc = calc;           //4*2= 8 &   8 = 8  -same for all lower numbers
	      }                                               
	    iCCN = iCCN / 10;  // subtracts right most digit from ccNum
	    iTotal += calc;  // running total of the card number as we loop
	  }  // END OF LOOP
	  if ((iTotal%10)==0){  // check to see if the sum Mod 10 is zero
	    bResult = true;  // This IS (or could be) a valid credit card number.
	  } else {
	    bResult = false;  // This could NOT be a valid credit card number
	    }
	  }
	}
  return bResult; // Return the results
}