var CRM_FORM_TYPE_CREATE = 1;
var CRM_FORM_TYPE_UPDATE = 2;
switch (crmForm.FormType)
	{
	case CRM_FORM_TYPE_CREATE:
	crmForm.all.new_openddate.DataValue = new Date();
	break;

	case CRM_FORM_TYPE_UPDATE:
	// do nothing
	break;
	}

if(crmForm.all.new_salesstageid.DataValue != null && crmForm.all.new_salesstageid.DataValue[0].name != "1")
crmForm.SetFieldReqLevel("new_projectmanagerid", 1);

else

crmForm.SetFieldReqLevel("new_projectmanagerid", 0);

And here is an example that works with multipe options

if(crmForm.all.new_salesstageid.DataValue != null) {

    switch(crmForm.all.new_salesstageid.DataValue[0].name) {
        case "1":
        case "2":
            crmForm.SetFieldReqLevel("new_projectmanagerid", 1);
            break;
        default:
             crmForm.SetFieldReqLevel("new_projectmanagerid", 0);
      break;
    }

}
else
{
    crmForm.SetFieldReqLevel("new_projectmanagerid", 0);
}

// Builds a string for the source attribute of an IFrame
// Credit is given to Michael Hohne and Andrew Zimmer for the following code.  For additional information, please
// refer to his stunnware site: http://www.stunnware.com/crm2/topic.aspx?id=JS27
//for formatting the IFRAME: http://blogs.inetium.com/blogs/azimmer/archive/2010/01/14/crm-displaying-related-entity-in-iframe-slightly-improved.aspx

function GetFrameSource(tabSet, roleOrd) {

    if (crmForm.ObjectId != null) {

        var roleOrdParamMissing = (typeof(roleOrd) == "undefined") || (roleOrd == null);

        var oId = crmForm.ObjectId;
        var oType = crmForm.ObjectTypeCode;
        var security = crmFormSubmit.crmFormSubmitSecurity.value;

        var url = "areas.aspx?oId=" + oId + "&oType=" + oType + "&security=" + security + "&tabSet=" + tabSet;

        if (!roleOrdParamMissing) {
            url += "&roleOrd=" + roleOrd;
        }

        return url;
    }

    else {
        return "about:blank";
    }
}

 // Waits for the content window of the IFrame to be ready
  function FixStylingInFrameSource(iframeID) {
      // Check the content window's ready state
      if (document.getElementById(iframeID).contentWindow.document.readyState
!= "complete") {
          // Re-run this function in 10 ticks
          window.setTimeout(function() { FixStylingInFrameSource(iframeID) }, 10);
      }
      // Content window is ready
      else {
          // Change the background color
          document.getElementById(iframeID).contentWindow.document.body.style.backgroundColor = "#eef0f6";
          // Remove the left border
          document.getElementById(iframeID).contentWindow.document.body.all(0).style.borderLeftStyle = "none";
          // Remove padding
          document.getElementById(iframeID).contentWindow.document.body.all(0).all(0).all(0).all(0).style.padding = "0px";

          // Make the cell the full width of the IFRAME
         document.getElementById(iframeID).contentWindow.document.body.all(0).style.width = "102%"

          // Show the IFrame
          document.getElementById(iframeID).style.display = "block";
      }
  }

crmForm.all.IFRAME_organizaton_programs.src = GetFrameSource("new_account_organizationswithprograms");

if(crmForm.FormType != 1)
{
FixStylingInFrameSource('IFRAME_organizaton_programs');
}

To start update new_OpportunityID and new_ContactID with your fields, this example concatenates the Opportunity ID and Contact ID lookup fields.

var lookupItemOppID = new Array;
lookupItemOppID = crmForm.all.new_OpportunityID.DataValue;

var vOpportunityID= (lookupItemOppID[0] != null) ? lookupItemOppID[0].name : "";

var lookupItemConID = new Array;
lookupItemConID = crmForm.all.new_ContactID.DataValue;

var vContactID= (lookupItemConID[0] != null) ? lookupItemConID[0].name : "";

CrmForm.all.new_name.DataValue = vOpportunityID + " - " + vContactID;

This will concatenate two normal fields

crmForm.new_fullname.DataValue = crmForm.new_firstname.DataValue + " " + crmForm.new_lastname.DataValue;

This will concatenate a lookup field and a normal text field

if(crmForm.all.new_abreviationid.DataValue!=null)

var nameval=crmForm.all.new_abreviationid.DataValue[0].name;

crmForm.all.new_uasi.DataValue=nameval+","+crmForm.all.new_name.DataValue;

Then once you have the field completed you will want to force the change to the database. This will be necessary when a user changes one of the values that creates the concatentated field. It will show the change on the form, however it will not force the change to the database.

//force the result to the database
crmForm.all.DesiredField.ForceSubmit = true

This is a great white paper that has come into use for an enterprise solution I am working with on a client site. This document covers Connectivity and Firewall Port Requirements in On-Premise Deployments for Dynamics CRM 4.0.

Overview
Many data centers include firewalls between the end-users and the servers and other integrated systems that support an implementation of Microsoft Dynamics CRM 4.0. This document provides guidance on the connectivity requirements between Microsoft Dynamics CRM 4.0 and other systems to assist readers with proper firewall configuration in customer environments.

This is interesting. Looks like others have been searcing perhaps?

Note This is a “FAST PUBLISH” article created directly from within the Microsoft support organization. The information contained herein is provided as-is in response to emerging issues. As a result of the speed in making it available, the materials may include typographical errors and may be revised at any time without notice. See Terms of Use (http://go.microsoft.com/fwlink/?LinkId=151500) for other considerations.

crmForm.new_fullname.DataValue = crmForm.new_firstname.DataValue + " " + crmForm.new_lastname.DataValue