/*
 * Some Javascripts :)
 */

//Function to simulate the <blink> tag. Use on spans.
function blink(elementID,onoff){

//element = document.getElementById(elementID);

  if (onoff == 1)
  {
  changeOpac(0, elementID)
  setTimeout('blink("'+elementID+'",0)',500);
  }
  else
  {
  changeOpac(100, elementID)
  setTimeout('blink("'+elementID+'",1)',500);
  }

}

//TODO: Function to simulate marquee tags. Can be less generalized as we should only really be using it one place in the site.



// OPACITY FUNCTIONS:


function opacity(id, opacStart, opacEnd, millisec) {
    //speed for each frame
    var speed = Math.round(millisec / 100);
    var timer = 0;

    //determine the direction for the blending, if start and end are the same nothing happens
    if(opacStart > opacEnd) {
        for(i = opacStart; i >= opacEnd; i--) {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    } else if(opacStart < opacEnd) {
        for(i = opacStart; i <= opacEnd; i++)
            {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    }
}

//change the opacity for different browsers
function changeOpac(opacity, id) {
    var object = document.getElementById(id).style; 
    object.opacity = (opacity / 100);
    object.MozOpacity = (opacity / 100);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
}

function shiftOpacity(id, millisec) {
    //if an element is invisible, make it visible, else make it ivisible
    if(document.getElementById(id).style.opacity == 0) {
        opacity(id, 0, 100, millisec);
    } else {
        opacity(id, 100, 0, millisec);
    }
}

function blendimage(divid, imagefile, millisec) {
    var speed = Math.round(millisec / 100);
    var timer = 0;

    
    
    //document.getElementById(divid).style.backgroundImage = "url(" + document.getElementById(divid2).style.backgroundImage + ")";
    //changeOpac(0, divid2);
    document.getElementById(divid).style.backgroundImage = "url(" + imagefile+ ")";;

    
    for(i = 0; i <= 100; i++) {
        setTimeout("changeOpac(" + i + ",'" + divid + "')",(timer * speed));
        timer++;
    }
}

function currentOpac(id, opacEnd, millisec) {
    //standard opacity is 100
    var currentOpac = 100;
    
    //if the element has an opacity set, get it
    if(document.getElementById(id).style.opacity < 100) {
        currentOpac = document.getElementById(id).style.opacity * 100;
    }

    //call for the function that changes the opacity
    opacity(id, currentOpac, opacEnd, millisec)
}