function checkavailable(str) {

	if (str.length > 0)
	{ 
		var url="ajax.php?action=newreg&value=" + str;
		xmlHttp.open("GET", url , true);
		xmlHttp.onreadystatechange=function() { 
  			if(xmlHttp.readyState==4 ){ 
					
		   			if(trim(xmlHttp.responseText)=="invalid"){
			   		
						alert("This user name already exists!");
		   				document.getElementById("username").value="";
		   				document.getElementById("username").focus()
					}
  			} 
 		}		
		xmlHttp.send(null)
	 } 
}
function checkvalid(str) {

	if (str.length > 0)
	{ 
		var url="ajax.php?action=login&value=" + str;
		xmlHttp.open("GET", url , true);
		xmlHttp.onreadystatechange=function() { 
  			if(xmlHttp.readyState==4 ){ 
					
		   			if(trim(xmlHttp.responseText)=="invalid"){
			   		
						alert("This user name does not exists!");
		   				document.getElementById("login_username").value="";
		   				document.getElementById("login_username").focus()
					}
  			} 
 		}		
		xmlHttp.send(null)
	 } 
}
function validate(){

		if (document.getElementById("username").value==""){
		
			alert("Please enter username");
			document.getElementById("username").focus();
			return false;
		
		}else if(document.getElementById("password").value==""){
		
			alert("Please enter password");
			document.getElementById("password").focus();			
			return false;			
		
		}else if(document.getElementById("email").value==""){
		
			alert("Please enter email");
			document.getElementById("email").focus();			
			return false;			
		
		}else if(!checkMail(document.getElementById("email").value)){
		
			alert("Please enter a valid email");
			document.getElementById("email").focus();			
			return false;			
		
		}else{
		
			document.getElementById("frmRegister").action="index.php?act=register";
			document.getElementById("frmRegister").submit();
		
		} 

}
function login(){

		if (document.getElementById("login_username").value==""){
		
			alert("Please enter username");
			document.getElementById("login_username").focus();
			return false;
		
		}else if(document.getElementById("login_password").value==""){
		
			alert("Please enter password");
			document.getElementById("login_password").focus();			
			return false;			
		
		}else{
		
			document.getElementById("frmLogin").action="index.php?act=login";
			document.getElementById("frmLogin").submit();
		
		} 

}
function checkMail(email)
{
        var str1=email;
        var arr=str1.split('@');
        var eFlag=true;
        if(arr.length != 2)
        {
                eFlag = false;
        }
        else if(arr[0].length <= 0 || arr[0].indexOf(' ') != -1 || arr[0].indexOf("'") != -1 || arr[0].indexOf('"') != -1 || arr[1].indexOf('.') == -1)
        {
                        eFlag = false;
        }
        else
        {
                var dot=arr[1].split('.');
                if(dot.length < 2)
                {
                        eFlag = false;
                }
                else
                {
                        if(dot[0].length <= 0 || dot[0].indexOf(' ') != -1 || dot[0].indexOf('"') != -1 || dot[0].indexOf("'") != -1)
                        {
                                eFlag = false;
                        }

                        for(i=1;i < dot.length;i++)
                        {
                                if(dot[i].length <= 0 || dot[i].indexOf(' ') != -1 || dot[i].indexOf('"') != -1 || dot[i].indexOf("'") != -1 || dot[i].length > 4)
                                {
                                        eFlag = false;
                                }
                        }
                }
        }
                return eFlag;
}