JavaScrip command getElementById useful examples
-Sets page field(ID=field1) to read only
document.getElementById("field1").readOnly="readonly";
-Gets value of page field(ID=field1) and stores it in new variable fieldval
var fieldval = document.getElementById("field1").value;
-Gets value of page field(ID=field1) and stores it in second page field(ID=Field2)
document.getElementById("field2").value = document.getElementById("field1").value;
-Add two page fields togther and store result in variable fieldval
var fieldval = document.getElementById("field1").value + document.getElementById("field2").value;
-Add two page fields togther and store result in another page field
var document.getElementById("field3").value = document.getElementById("field1").value + document.getElementById("field2").value;
-Sets a checkbox(ID=check1) to checked or not
document.getElementById('check1').checked=true; <!--Checked-->
document.getElementById('check1').checked=false; <!--Unchecked-->
Same using GetElementByName
checkboxes = document.getElementsByName("check1");
checkboxes[0].checked = true;
-Sets field(ID=field1) to disabled or not
document.getElementById("field1").disabled = false; <!--Not disbaled-->
document.getElementById("field1").disabled = true; <!--disbaled-->
-Set visibility style attribute to Hide/Show field(ID=field1)
document.getElementById("field1").style.visibility = 'hidden';
document.getElementById("field1").style.visibility = 'visible';
-Set display style for field(ID=field1) to display/remove field
document.getElementById("field1").style.display = 'block';
document.getElementById("field1").style.display = 'none';