// --------check for null value---------

function checkNull(str)
{
 if (str == "")
 {
	isvalid=false;
	return isvalid;
 }
 else
 {
  if(!trim(str))
  {
	isvalid=false;
	return isvalid;
  }
  else
  {
	return true;
  }
 }
}

//--------check for number--------

function checkNum(str)
{
 ch=""
 strlen=str.length;
 for (i=0;i<strlen;i++)
 {
	ch=str.charAt(i)
    if ( ch<"0" || ch>"9" )
	{
		return false;
	}
 }
 return true;
}

//----------check for special characters---------

function checkSp(str)
{
 var myval;
 myval=true;
 ch=""
 strlen=str.length;
 for (i=0;i<strlen;i++)
 {
	ch=str.charAt(i);
	if ( !(
		   (ch>="0" && ch<="9") ||
		   (ch>="a" && ch<="z") ||
         (ch>="A" && ch<="Z")) 
      )
	{
		return false;

    }
 }
 return true;
}

//------------removes leading spaces-----------

function trim(str)
{
  while(str.substring(0,1) == " ")
	{
		str= str.substring(1,str.length)
	}

		if(str == "") 
		{
			isvalid=false;
			return isvalid;
		}
		else
		{
			isvalid=true;
			return isvalid;
		}
 }

//--------radiobutton / checkbox is checked--------

function isChecked(strobj)   
{
  var myval = true;
  var checkok1;

		for (i = 0; i < strobj.length; i++)
		{
			if (strobj[i].checked) 
				checkok1 = "OK";
		}
		
		if (checkok1 == "OK") 
		{
		//	myval=true;	//added later
		}
		else 
		{
			myval = false;
	 	}
		return myval;		
}

//----------checks for valid email----------

function checkMail(str)
{
	var atpos,dotpos,strlen,ctr,ctr1;
	strlen=str.length;
	ctr=0;
	ctr1=0;
	var arr=new Array("~","`","!","#","$","%","^","&","*","-","+","=","|",":",";","'","<",">",",","?","/","\\","\"")			
	
	atpos=str.indexOf("@")
	nextat=atpos+1
	ldotpos=str.lastIndexOf(".")	
	fdotpos=str.indexOf(".")
	for (i=0;i<strlen;i++)
	{
		dotpos=str.indexOf(".",i+1)
		satpos=str.indexOf("@",nextat)

		for (j=0;j<arr.length;j++) 
		{
			if ( (str.charAt(i)==" ") || (atpos==0) || ((ldotpos+1)==strlen) || (fdotpos<atpos) ||(str.charAt(dotpos+1)==".") || (atpos==-1) || (fdotpos==-1) || (str.charAt(atpos+1)==".") || (satpos != -1) || (str.charAt(i)==arr[j]) )
			
		{
		//	alert("invalid");
			return false;
		}

	}	//for j loop

	nextat=nextat+1

	}
	return true;
}

function checkTextArea(str)
{
	var strlen;
	var hasChar;
	strlen = str.length;
	j=0
	hasChar = true
	if(strlen == "") 
	{
		hasChar = false;
		return hasChar
	}
	else
	{
		for (i=0;i<=strlen;i++)
		{
			if (escape(str.substring(i,i+1)) == "%0D")
			{
				j += 2
			}
			if( str.substring(i,i+1) == " " )
			{
				j += 1
			}
		}
		if ( j == strlen )
		{
			hasChar = false;
			return hasChar
		}
		else
		{
			hasChar = true
			return hasChar
		}
	}
}