Checkbox in crm 4.0

yes,it is possible to create checkbox in crm 4.0

the step which you have to follow is...

• create one picklist named new_picklist(you can keep different name also but then you have to change the name in the following code).
• then create another text attribute to store the value of checkbox.
• then put the following code in the Onload event of the form.

var PL = crmForm.all.new_picklist;
var PLV = crmForm.all.new_picklistvalue;

if( PL != null && PLV != null )
{
  PL.style.display = "none";
  PLV.style.display = "none";

  // Create a DIV container
  var addDiv = document.createElement("<div style='overflow-y:auto; height:80px; border:1px #6699cc solid; background-color:#ffffff;' />');
  PL.parentNode.appendChild(addDiv);

  // Initialise checkbox controls
  for( var i = 1; i < PL.options.length; i++ )
  {
    var pOption = PL.options[i];
    if( !IsChecked( pOption.text ) )
      var addInput = document.createElement("<input type='checkbox' style='border:none; width:25px; align:left;' />' );
    else
      var addInput = document.createElement("<input type='checkbox' checked='checked' style='border:none; width:25px; align:left;' />' );
 
    var addLabel = document.createElement( "<label />");
    addLabel.innerText = pOption.text;
 
    var addBr = document.createElement( "
"); //it's a 'br' flag
 
    PL.nextSibling.appendChild(addInput);
    PL.nextSibling.appendChild(addLabel);
    PL.nextSibling.appendChild(addBr);
  }
 
  // Check if it is selected
  function IsChecked( pText )
  {
    if(PLV.value != "")
    {
      var PLVT = PLV.value.split("||");
      for( var i = 0; i < PLVT.length; i++ )
      {
        if( PLVT[i] == pText )
          return true;
      }
    }
    return false;
  }
 
  // Save the selected text, this filed can also be used in Advanced Find
  crmForm.attachEvent( "onsave" , OnSave);
  function OnSave()
  {
    PLV.value = "";
    var getInput = PL.nextSibling.getElementsByTagName("input");
 
    for( var i = 0; i < getInput.length; i++ )
    {
      if( getInput[i].checked)
      {
        PLV.value += getInput[i].nextSibling.innerText + "||";
      }
    }
  }
}