var ie = document.all?true:false;
var ns = document.layers?true:false;

//when blank field is not allowed
function blankchk(x){
	if (x.value=="" ){
		alert("you hafta fill in somethin");
		x.focus();
		return false;
	}
	return true;
}

//validation for phone numbers
function phonechk(x){	
	var num=/[0-9\-\s]+/
	numflag=x.value.match(num);	
	if(numflag != x.value){
		alert("Please enter valid phone number")
		x.focus();
 		x.select();
		return false;
	}
	return true;
}

//Only numbers are allowed
function numchk(x){	
	var num=/[0-9\.]+/
	numflag=x.value.match(num);	
	if(numflag != x.value){
		alert("Please enter numbers only")
		x.focus();
 		x.select();
		return false;
	}
	return true;
}

//Email validation
function emailchk(x){
	var email =/[-a-zA-Z0-9_\.]+@[-a-zA-Z0-9]+\.[-a-zA-Z0-9\.]+/;
	var eflag = x.value.match(email);
	if(eflag!=x.value){
		alert("not a valid @")
		x.focus();
		x.select();
		return false;
	}
	return true;
}

//Only alphabets are allowed
function alphachk(x){
	var alpha=/[a-zA-Z]+/
	alphaflag=x.value.match(alpha);	
	if(alphaflag != x.value){
		alert("Please enter alphabets only.")
		x.focus();
 		x.select();
		return false;
	}
	return true;
}	

//Validation for userid, where alphanumeric and under score is allowed
function useridchk(x){
	var usr=/[a-zA-Z0-9\_]+/;
	uidflag=x.value.match(usr);	
	if(uidflag != x.value){
		alert("Please enter valid user id.")
		x.focus();
 		x.select();
		return false;
	}
	return true;
}

//First element of dropdown cannot be selected
function dropdownchk(x){
	if(x.options[0].selected=="true"){
		alert("Please select one option from the drop down box");
		x.options[0].focus();
		return false;
	}
	return true;
}

//Validation when for confirm password
function confpswdchk(pass, confpass){
	if(confpass.value != pass.value){
		alert("The confirm password should be same as password");
		confpass.focus();
		confpass.select();
		return false;
	}
	return true;
}

//Validation where only Alphabets and space is allowed.
function alphaspchk(x){
	var sp=/[a-zA-Z\s]+/;
	alpflag=x.value.match(sp);	
	if(alpflag != x.value){
		alert("nothing but A-Z, a-z & space")
		x.focus();
 		x.select();
		return false;
	}
	return true;
}

//validation of the date field
function datechk(dd,mm,yyyy){
	switch(chkdate(dd,mm,yyyy)){
		case 1:
			alert("Invalid From Day");
			return false;
			break;
		case 2:
			alert("Invalid From Month");
			return false;				
			break;
		case 3:
			alert("Invalid From Year");
			return false;
			break;
		case 4:
			alert("This month has only 30 days");
			return false;
			break;
		case 5:
			alert("This is a leap year. Feb has only 29 days");
			return false;
			break;
		case 6:
			alert("This is not a leap year. Feb has only 28 days");
			return false;
			break;
		case 7:
			alert("This year is a leap year. Feb has only 29 days");
			return false;
			break;
		case 8:
			alert("The \"date\" cannot be greater than today\'s date");
			return false;
			break;
	}
	return true;
}
			
function chkdate(dd,mm,yyyy){
	var dt = new Date();
	invdate=mm+"/"+dd+"/"+yyyy;
	var invdate=new Date(invdate);
	sysdate = dt.getUTCMonth()+1 + '/' + dt.getUTCDate() + '/' + dt.getUTCFullYear();
	var sysdate=new Date(sysdate);
	if(dd==0 || dd>31) return 1; 
	if(mm==0 || mm>12) return 2;
	if(yyyy==0) return 3;
	if ((mm==4||mm==6||mm==9||mm==11) && (dd>30)) return 4;
	if(mm==2 && dd>29 && yyyy %400==0) return 5;
	if(mm==2 && dd>28 && yyyy % 4!=0) return 6;
	if(mm==2 && dd>29 && yyyy % 4==0 && yyyy %400!=0) return 7;
	if (sysdate < invdate) return 8;
}	

function chkbox(chk){
	var flag=false;
	var val=new Array();
	var a=0;
	if(ie){
		if(!isNaN(chk.length)){
			for(i=0;i<chk.length;i++){
				if(chk[i].checked==true){
					flag=true;
					val[a]=chk[i].value;
					a++;
				}
			}
		}else{
			if(isNaN(chk.length)){
				if(chk.checked==true){
					flag=true;
					val[a]=chk.value;
				}
			}
		}
		
		if(flag==false){
			alert("Please select your choice.");
			return false;
		}
		for(ctr=0;ctr<val.length;ctr++){
			alert(ctr+" = "+val[ctr]);
		}
			
	}
	if(ns){
		if(chk.length>0){
			for(i=0;i<chk.length;i++){
				if(chk[i].checked==true){
					flag=true;
					val[a]=chk[i];
					a++;
				}
			}
		}else{
			if(chk.length<=0){
				if(chk.checked==true){
					flag=true;
					val[a]=chk.value;
				}
			}
		}
	
		if(flag==false){
			alert("Please select your choice.");
			return false;
		}
	}	
}