function isAlphabetNumeric(strData){
var iCount,iDataLen;
var strCompare;
var bFlag = true;
strCompare = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
iDataLen = strData.length;
if (iDataLen >0){
for (iCount=0; iCount{
var cData = strData.charAt(iCount);
if (strCompare.indexOf(cData) < 0 ){
alert("Character "+ cData +" not allowed")
return false;
} 
}
return true;
}
else{
return false;
}
}