function isNull(aStr)
{      
    var index;
    for (index=0; index < aStr.length; index++)
            if (aStr.charAt(index) != ' ')
                    return false;
                                
    return true;
}

function checkSearch(form)
{ 
	var err; 
	var valid = "#@$!%^&/<>;\][}{=";
	x = form.txtSearch.value
	if (x.length<3)
	{
        alert("String Entered Should be meaningful & more than 3 Letters. Thank you");
        form.txtSearch.focus();
        return false;
	}
   	for (var i=0; i< x.length; i++)
   	{
   		temp = x.substring(i,i+1);

		if (valid.indexOf(temp)!= "-1")
   		{
			err = 1;
			break;
		}

	    else
		{
   			err=0;
		}
 	}
	if(err==1)
	{
		alert("Please use only alpha numeric charachters.");
		form.txtSearch.value="";
		form.txtSearch.focus();
        return false;
	}

    if (isNull(form.txtSearch.value)) 
	{
        alert("Please Enter Your Search word");
        form.txtSearch.focus();
        return false;
    }

	form.action="/sitesearch/sitesearch.asp";
	form.submit();    
}